The Missile Age begins when German V-2 missiles -- which have one-ton payloads and travel faster than the speed of sound -- strike London during World War II. It is later learned that the Germans had plans to develop intercontinental ballistic missiles (ICBMs) as well.

In July 1945, military officers recommend that the U.S. start researching and developing ways to defend against incoming ballistic missiles. A military advisory group discusses the idea of using an "energy beam" to defend the U.S. against ballistic missiles in December 1945, and two military studies are initiated three months later to explore the use of possible "interceptor" missiles to destroy incoming warheads.

At the height of the Cold War, the Soviet Union tests the first ICBM. Two months later, it launches Sputnik (the first earth-orbiting satellite) into space.

Four months after the Soviets test the first ICBM, the U.S. successfully launches its own: an Atlas ICBM.

The U.S. steps up its missile defense efforts after the Soviet test and Sputnik launch and begins work on the Nike-Zeus system, its first major anti-ballistic missile system. A ground-based system, Nike-Zeus calls for nuclear-armed interceptors to get close enough to enemy warheads in space to destroy them. Meanwhile, the Pentagon explores technologies that could be used to intercept enemy missiles in their boost phases.

The Soviet Union demonstrates ABM capabilities when it successfully intercepts its first a ballistic missile. The ABM missile uses a high-explosive payload to destroy its target.

One of the Army's Zeus missile interceptors, launched from Kwajalein Atoll in the Marshall Islands, comes within 2 km of a mock warhead that had been fired from California, which is close enough for a nuclear blast to destroy the warhead.

President Kennedy announces to the nation that there are nuclear missile sites in Cuba and that he has ordered a naval blockade of the island. After a series of tense negotiations, the worst of the missile crisis ends when the Soviet Union agrees to remove its missiles from Cuba. Privately, Attorney General Robert F. Kennedy informs the Soviet Union that the U.S. will withdraw its own missiles from Turkey once the crisis ends.

Another Army interceptor missile comes within 200 meters of a mock warhead, again close enough to destroy it with a nuclear explosion.

Nike-Zeus is replaced by the Nike X research program. It is conceived as a "layered" defense, in which long-range interceptors would home in on the enemy warhead in space while short-range interceptors would attack any warheads that re-entered the atmosphere.

China launches its first nuclear missile.

The U.S. publicly confirms that the Soviet Union is deploying its anti-ballistic missile (ABM) system around Moscow, which it had first detected two years earlier.

The U.S. announces plans to proceed with its Sentinel ABM system (successor to Nike X), which calls for deploying 700 interceptors to defend selected cities from a limited Chinese threat.

The Outer Space Treaty, signed by the U.S., the Soviet Union, and dozens of other countries, mandates that countries will not place "in orbit around the earth any objects carrying nuclear weapons or any other kinds of weapons of mass destruction."

After a series of public demonstrations protesting the military's plans to deploy nuclear-armed interceptor missiles near populated areas, the U.S. announces it will halt the deployment of Sentinel. At the time of the announcement, Richard Nixon has been president less than a month.

President Nixon says the deployment of a missile defense will continue. The system is now dubbed "Safeguard," and instead of defending metropolitan areas, the system will use nuclear-armed missiles to defend U.S. ICBM silos.

After months of debate, Congress narrowly approves plans to fund Safeguard; Nixon's vice president, Spiro Agnew, casts the tie-breaking vote.

Nixon and Soviet General Secretary Leonid Brezhnev sign the first Strategic Arms Limitation Treaty (SALT I), which includes the Anti-Ballistic Missile (ABM) Treaty. The ABM Treaty prohibits a nation-wide missile defense, but allows each side two ABM deployment sites and a maximum of 100 interceptor missiles.

An amendment to the ABM Treaty reduces the number of ABM deployment sites for each superpower to one.

The Safeguard ABM site in Grand Forks, N.D., becomes operational in October. By November, both houses of Congress have decided to cancel funding for the Safeguard system, partly on the grounds that it will be too expensive and ineffective against new Soviet weapons.

The Safeguard ABM site in North Dakota is deactivated after just 133 days in operation.

U.S. President Ronald Reagan, in a nationally televised address, calls for research and development of into missile defenses: "I call upon the scientific community in our country, those who gave us nuclear weapons, to turn their great talents now to the cause of mankind and world peace, to give us the means of rendering these nuclear weapons impotent and obsolete." The next day, congressional opponents of the president's plan deride it as "Star Wars." On March 25, 1983, the president formalizes his policy in National Security Decision Directive 85.

Reagan's new missile defense program is further codified in National Security Decision Directive 119, which says that "the SDI is not a development and deployment program, but rather a broad-based, centrally managed research effort to identify and develop the key technologies necessary for an effective strategic defense. The research will be initially focused on technologies for: sensing and tracking attacking missiles; destroying attacking missiles and warheads; command and control; and survivability and sustainability."

Reagan's secretary of defense, Caspar Weinberger, signs the charter for the Strategic Defense Initiative Organization (SDIO).

After several failed attempts, the Army successfully tests its Homing Overlay Experiment (HOE), in which a "kill vehicle" launched atop a booster rocket from Kwajalein Atoll in the Marshall Islands homes in on its target -- an ICBM launched from Vandenberg A.F.B. in California -- and destroys it. (Nearly a decade later, however, the General Accounting Office issues a report indicating that the test had been partly rigged.)

In what The Washington Post hails as a "first for 'Star Wars,'" a laser beam fired from Hawaii is able to bounce off a mirror on the space shuttle Discovery, which is 230 miles above earth and traveling 17,500 mph. The Post quotes the manager of the laser program, U.S. Air Force Lt. Col. Thomas Meyer, as saying, "Our next step is to perform the same kind of test with rockets fired to an altitude of 360 miles to see if ground-based lasers can stay with them all the way."

At the White Sands Missile Range in New Mexico, a chemical laser aimed at a missile body, which is on the ground and immobile, is able to destroy the missile shell by irradiating it. The New York Times reports that "the use of powerful lasers against missiles in flight is foreseen as one likely component of a defense against Soviet missile attack." It further states, however, that the test "did not appear to represent a breakthrough, since chemical lasers have destroyed metallic objects in the past."

In confirmation hearings, President George H.W. Bush's nominee for secretary of defense, John Tower, says, "I don't believe that we can devise a [ballistic missile defense] umbrella that can protect the entire American population from nuclear incineration. I think that's unrealistic." The New York Times reports that Tower's comments are "a milestone in the history of the anti-missile program." Though Tower is not confirmed, Bush's new secretary of defense -- Dick Cheney -- and other administration officials continue gingerly to echo Tower's sentiments.

At a congressional hearing, Secretary of Defense Dick Cheney says that budget limitations will delay the development of SDI programs. Cheney also says that the Bush administration will emphasize "Brilliant Pebbles," a missile defense concept in which thousands of small interceptor rockets orbiting in space would home in on enemy missiles and destroy them in their initial or boost phases.

Amid warming relations between the U.S. and the Soviet Union, Richard Perle, assistant secretary of defense in the Reagan administration and an influential policy adviser, tells a congressional committee, "I believe we can safely reduce the investment we make in protecting against a massive surprise Soviet nuclear attack."

Shortly after the Gulf War begins, press reports indicate that for the first time in history, an U.S. ABM anti-missile system (the Patriot) has intercepted and destroyed its target (an Iraqi Scud) under combat conditions. (It is later revealed that the Patriot's success during the Gulf War had been greatly exaggerated.)

The Pentagon's Exoatmospheric Reentry Vehicle Interceptor System (ERIS), which was built using technology from the SDI's Homing Overlay Experiment, reportedly hits and kills a mock target in space. The New York Times reports that "after seven years of research and $24 billion in spending, the Pentagon's 'Star Wars' program to destroy enemy missiles has achieved its first interception of a mock warhead in space." Critics maintain that the test is plagued by artificial conditions that make success near certain.

In his State of the Union address, President Bush scales back SDI and proposes what becomes GPALS, or Global Protection Against Limited Strikes. "With remarkable technological advances like the Patriot missile, we can defend against ballistic missile attacks aimed at innocent civilians," says Bush. "Looking forward, I have directed that the SDI program be refocused on providing protection from limited ballistic missile strikes, whatever their source."

President Bush and Soviet President Mikhail Gorbachev conclude the first Strategic Arms Reduction Treaty (START I). The two leaders agree to reduce their arsenals to 6,000 warheads and 1,600 total ICBMs, submarine-launched ballistic missiles, and heavy bombers.

President Bush signs the Missile Defense Act of 1991, which mandates that the Department of Defense develop by 1996 a "a cost effective, operationally effective, and ABM Treaty-compliant anti-ballistic missile system" that will protect the U.S. from limited threats. It also requires the Defense Department to "aggressively pursue" theater missile defenses to protect U.S. troops in the field.

Amid political upheaval, the leaders of Russia, Ukraine, and Belarus declare that the Soviet Union is dissolved. Gorbachev rejects their right to determine the Soviet Union's fate, but later that month, the Soviet Union officially dissolves and the Commonwealth of Independent States emerges, effectively ending the Cold War.

In its second hit-to-kill attempt, the ERIS kill vehicle misses its target warhead by several meters.

Nearly three weeks before he is to leave office, President Bush signs the START II agreement with Russian President Boris Yeltsin, which would reduce nuclear arsenals once again, to 3,000-3,500 warheads each by 2003.

In renaming SDIO the Ballistic Missile Defense Organization (BMDO), Secretary of Defense Les Aspin declares "the end of the Star Wars era." The BMDO's emphasis will be on developing theater missile defenses.

The Republicans announce the National Security Restoration Act, which is part of its "Contract With America" platform. It calls for the Defense Department to "develop for deployment at the earliest possible date a cost-effective, operational anti-ballistic missile defense system to protect the U.S. against ballistic missile threats." In November, the Republicans sweep both houses of Congress.

After heated debate, the House of Representatives defeats by a vote of 218-212 the portion of the "Contract with America" that would mandate a national missile defense system.

The National Intelligence Council, which is made up of 13 intelligence agencies, releases its 1995 National Intelligence Estimate (NIE), which concludes that "no country, other than the major declared nuclear powers, will develop or otherwise acquire a ballistic missile in the next 15 years that could threaten the contiguous 48 states or Canada." When the unclassified summary of the NIE begins to circulate on Capitol Hill, Republicans charge that it had been leaked to help defeat missile defense, and GOP leaders order an outside panel to examine whether the political process had influenced the intelligence community's findings.

House leader Newt Gingrich and Senate Majority leader Robert Dole introduce the Defend America Act, which would require the U.S. to deploy by 2003 a national missile system that would provide a "highly effective" defense to all 50 states against limited, unauthorized, and accidental launches.

In congressional testimony, Secretary of Defense William Perry outlines the Pentagon's "three-plus-three" National Missile Defense (NMD) program, which provides for the development and demonstration of a national missile defense system within three years, or by 2000. The administration would then make a deployment decision and, if the threat warranted, the system would be deployed within three years, or by 2003.

The Congressional Budget Office reports that deployment of the Defend America Act could cost up to $60 billion -- much more than originally anticipated. Subsequently, the bill never comes up for a vote.

The outside panel ordered to examine the NIE 95 intelligence findings, issues its report. The panel is chaired by Robert Gates, deputy national security adviser and director of the CIA during the first Bush administration. In presenting the panel's findings to Congress, Gates says, "The panel believes the intelligence community has a strong case that for sound technical reasons, the United States is unlikely to face an indigenously developed and tested intercontinental ballistic missile threat from the Third World before 2010." Further, says Gates, "There was no breach of the integrity of the intelligence process. Beyond this, the panel believes that unsubstantiated allegations challenging the integrity of intelligence community analysts by those who simply disagree with their conclusions, including by members of Congress, are irresponsible." Unsatisfied, congressional proponents of missile defense create another commission to assess ballistic missile threats (see Rumsfeld commission, below).

A summit between President Clinton and Russian President Boris Yeltsin takes place in Helsinki, Finland, amid Russian concerns over U.S. efforts to mandate a national missile defense system. Both sides signal that they are ready to proceed with START III negotiations, which would reduce each nation's arsenal of deployed nuclear weapons to 2,000-2,500. Additionally, after years of negotiations to reach a definition of acceptable "theater" missile defenses under the ABM Treaty, the two nations announce that they have reached an agreement in which both sides "have the option to establish and to deploy effective theater missile defense systems," so long as those defenses "will not pose a realistic threat to the strategic nuclear force of the other side."

The first "fly by" test of the National Missile Defense system is conducted. A package of sensors is launched from Kwajalein Atoll and it collects data in space on targets that have been launched by a missile from Vandenberg A.F.B. There is no attempt to intercept the targets.

Representatives from the U.S., Russia, Ukraine, Belarus, and Kazakhstan sign the ABM Treaty agreement on theater defense weapons.

The second NMD "fly by" test is conducted.

An independent panel chaired by retired Gen. Larry Welch issues its report on the Pentagon's missile defense testing programs. The panel says that the ambitious programs amount to a "rush to failure." The report's authors, which include several defense experts, urge a longer development period for missile defense weapons.

A bipartisan bill introduced by Sen. Thad Cochran (R-Miss.) would mandate that the U.S. "deploy as soon as is technologically possible an effective National Missile Defense system capable of defending the territory of the United States against limited ballistic missile attack (whether accidental, unauthorized, or deliberate)."

For the first time, Pakistan tests a missile with a reported range of 950 miles and the ability to carry a nuclear warhead of more than 1,500 pounds. The next month, both Pakistan and India test nuclear weapons.

The nuclear tests in South Asia set off intense debate over Sen. Cochran's American Missile Protection Act. "We're hearing the thunder now," said Sen. Fred Thompson (R-Tenn.), in remarks on the Senate floor. "It's ... reminding us that some countries are more technically clever than we give them credit for, and that outside assistance can dramatically accelerate technical progress." The attempt to debate the bill is defeated by a single vote.

The bipartisan Commission to Assess the Ballistic Missile Threat to the United States, known as the Rumsfeld commission, issues its report, which challenges the NIE 1995 findings. Former (and future) Secretary of Defense Donald Rumsfeld, who chairs the commission, says in congressional testimony, "This report says, unanimously, we need to assume that there may be no strategic warning about the development of a capability to hit the United States." Rumsfeld's commission concludes that a country like North Korea could deploy an ICBM "within about five years of a decision to develop" one.

In a test, North Korea for the first time demonstrates three-stage rocket technology in an attempt to launch a satellite into orbit. The satellite is carried atop a rocket that has been cobbled together from short-range Scud technology. The third stage explodes and the satellite is destroyed, but the failed North Korean test has a profound effect on U.S. policy.

In the aftermath of the North Korean launch, Senate Republicans again try to start debate on the American Missile Protection Act. As in their previous attempt in May, the vote to proceed to debate fails by one vote.

Eight Republican congressional leaders send a letter to President Clinton in which they write, "We have no choice but to conclude that the ABM Treaty did not survive the dissolution of the Soviet Union."

On Dec. 19, 1998, the House impeaches Clinton on two counts of perjury and obstruction of justice. On Feb. 12, 1999, his trial in the Senate finally ends with his acquittal.

"I have never advocated, initiated, encouraged, sanctioned, or blinked at the possibility that we could unilaterally abrogate the ABM Treaty," President Clinton says. "I personally would be very opposed to that."

With Clinton embroiled in scandal and the Democrats not eager to oppose missile defense, the Senate passes the National Missile Defense Act of 1999. It calls for the deployment of a national missile defense "as soon as technologically possible." The next day, the House passes a similar measure.

Clinton quietly signs the National Missile Defense Act, but in a statement says that "the legislation makes clear that no decision on deployment has been made."

The Washington Post reports that President Clinton, rejecting GOP insistence that the U.S. withdraw from the ABM Treaty, "has decided to ask Russia to agree initially to relatively modest changes in the 27-year-old [treaty]." The first set of changes, it reports, permit the U.S. to place 100 interceptor missiles in Alaska to defend against a limited attack from North Korea, Iraq, or Iran.

In a rare move, the intelligence community revises its 1995 National Intelligence Estimate and finally gives Congress the worst-case scenario some lawmakers have been seeking. It adopts the Rumsfeld commission's standard for measuring the threat: instead of what was likely to happen, it considered what could happen. The report says that "during the next 15 years the United States most likely will face ICBM threats from Russia, China, and North Korea, probably from Iran, and possibly from Iraq."

After five days of negotiations between U.S. and North Korean officials, North Korea pledges to suspend further long-range missile testing.

The first hit-to-kill test of Clinton's NMD system is conducted. Despite initial problems with its telescopes, the kill vehicle is able to locate the warhead and collide with it. [More details on the hit-to-kill tests.]

The second hit-to-kill test, which is more complex than the first, is conducted. The intercept fails when the kill vehicle misses the mock warhead by about 70 meters. [More details.]

The New York Times reports that "a former senior engineer at TRW, a top military contractor, has charged the company with faking tests and evaluations of a key component for the proposed $27 billion anti-missile system."

In a Congressional Budget Office report on the costs of the NMD system, the CBO says that "costs for the entire system would total nearly $49 billion through 2015." The Washington Post reports that the CBO's estimate is "roughly twice as much as Pentagon and congressional supporters of the program have estimated."

Presidential candidate George W. Bush holds a news conference at the National Press Club in which he says, "It is time to leave the Cold War behind and defend against the new threats of the 21st century. America must build effective missile defenses based on the best available options at the earliest possible date. Our missile defense must be designed to protect all 50 states and our friends and allies and deployed forces overseas from missile attacks by rogue nations or accidental launches." The next day, The New York Times reports that "in calling for missile defenses not only for the United States but also for its allies, Mr. Bush challenged the longtime orthodoxy of arms control: that prohibiting defenses allowed limits in offenses."

The third intercept test fails when the kill vehicle doesn't separate from its booster. [More details.]

Following the failed July test, Philip Coyle, director of the Pentagon's Office of Test and Evaluation, issues a devastating 67-page critique of the proposed national missile defense system (download in PDF). It details how the tests had been simplified to ensure the perception of success. The report is delivered privately to the president, but the Pentagon refuses for eight months to release Coyle's report to the public.

Clinton defers the decision over whether to deploy the National Missile Defense system to his successor. "I simply cannot conclude with the information I have today that we have enough confidence in the technology and the operational effectiveness of the entire [National Missile Defense] system to move forward to deployment."

In his confirmation hearing in front of the Senate Armed Services Committee, Bush's defense secretary nominee, Donald Rumsfeld, says that the ABM Treaty is "ancient history." Less than a week after Rumsfeld's comments, Gen. Colin Powell, Bush's nominee for secretary of state, says in his confirmation hearing before the Senate Foreign Relations Committee,that "it may be necessary, ultimately, to walk out of the ABM Treaty and abrogate our responsibilities." He adds, however, that he doesn't think it is currently necessary: "I think we've got a long way to go and we have a lot of conversations to have with the Russians over this. But the point I was making is that the framework that that treaty was designed for was a framework that really isn't relevant now."

Less than four months after taking office, President George W. Bush outlines his vision for missile defense in a speech at the National Defense University. "We need a new framework that allows us to build missile defenses to counter the different threats of today's world," Bush says, referring to what he deemed the ABM Treaty's limitations on research. "No treaty that prevents us from addressing today's threats, that prohibits us from pursuing promising technology to defend ourselves, our friends, and our allies is in our interests." Critics of Bush's plan say that the development of missile defenses could continue for many years without defying the ABM Treaty.

Rumsfeld submits an $8.3 billion request for missile defenses, the largest single weapons program in the Pentagon budget. Congress later approves a budget of $7.8 billion for missile defense.

The fourth NMD hit-to-kill test successfully demonstrates the system's interceptor capabilities. But during the final stages of the test, a software problem prevents the ground-based radar system from assessing the kill vehicle and whether or not it had hit the mock warhead. [More details.]

The Senate Armed Services Committee tries to move $600 million from the Pentagon's missile defense budget request into anti-terrorism efforts instead. Rumsfeld threatens a presidential veto.

The U.S. reels from attacks on the World Trade Center and the Pentagon.

Just weeks after the Sept. 11 attacks, the Defense Department releases its "Quadrennial Defense Review Report," in which it says that it has "refocused and revitalized the missile defense program, shifting from a single-site 'national' missile defense approach to a broad-based research, development, and testing effort aimed at deployment of layered missile defenses. ... These defenses will help protect U.S. forward-deployed forces. Moreover, they will provide limited defense against missile threats not only for the American people, but also for U.S. friends and allies."

The fifth hit-to-kill test of the NMD, which the Pentagon now calls the Ground-Based Midcourse Defense (GMD), takes place. Eight minutes after the kill vehicle separates from the booster, it homes in and destroys the target warhead. [More details.]

President Bush announces his intention to withdraw unilaterally from the ABM Treaty.

In announcing the reorganization of the BMDO, (it is now called the Missile Defense Agency), Rumsfeld says that a missile defense system would "defend the United States, deployed forces, allies and friends from ballistic missile attack." It also "layers defenses to intercept missiles in all phases of their flight (i.e. boost, midcourse, and terminal) against all ranges of threats." The Washington Post reports that the development plan for a "layered" missile defense is "a much more ambitious effort than the Pentagon's previous focus, which was largely on a ground-based interceptor system."

In its Pentagon budget request, the Bush administration earmarks $7.8 billion of the $367 billion defense budget for missile defense (the same amount approved for the previous year). Approximately 40 percent of the missile defense budget -- $3.2 billion -- is for the Bush administration's GMD system.

In the most recent test of the GMD, three decoys -- one large balloon and two smaller ones -- are used. Despite the additional decoys, the kill vehicle successfully homes in on the warhead and destroys it. [More details.]

Defense Daily reports that the MDA "has decided to classify details of the targets and countermeasures that will be used in all future [GMD] flight tests." Critics contend that the Pentagon is being unnecessarily secretive: "The devil is in the details," complains one congressman, "and the details are now classified."

The Washington Post reports that "in recent months, defense officials have exempted missile defense projects from the planning and reporting requirements normally applied to major acquisition programs. They have stopped providing Congress with detailed cost estimates and timetables for anti-missile systems."

The very day that the U.S. withdrawal from the ABM Treaty becomes effective, an experimental rocket fired from the USS Lake Erie in the Pacific Ocean shoots down a mock warhead fired from Kauai, Hawaii. (It is the fifth such test in a planned nine.) Critics maintain that the controlled conditions of the test permitted the intercept, and that the test did not effectively demonstrate a proficient defense against ICBMs.

Pentagon officials say that the new rules and changes in oversight are necessary. "The end result will be faster decision cycles while maintaining the highest standards of oversight," says Deputy Secretary of Defense Paul Wolfowitz at a congressional hearing. As for classifying decoy data, Wolfowitz says at same hearing, "We would be crazy not to do it. We regularly share that information with Congress, however, at whatever is the appropriate level of classification, and we will continue to do so. [But] there is absolutely no reason to share that information with our enemies."

As war with Iraq looms, the Bush administration releases its National Security Strategy for 2002, in which it reconsiders the notion of "deterrence," one of the hallmarks of military strategy during the Cold War. "Deterrence based only upon the threat of retaliation is less likely to work against leaders of rogue states more willing to take risks, gambling with the lives of their people, and the wealth of their nations," it says. Instead, the White House invokes the doctrine of "preemption": "We must be prepared to stop rogue states and their terrorist clients before they are able to threaten or use weapons of mass destruction against the United States and our allies and friends." Missile defense, the White House says, will still factor into the military strategy. "Our response must take full advantage of ... modern technologies, including the development of an effective missile defense system."