Nuclear Weapons and the U.S. Strategic Triad

When the United States first developed nuclear weapons, no one anticipated that the country would need three ways to deliver them. But, since the 1960s, U.S. nuclear weapons have been deployed by air, land, and sea. These three modes of delivery (and the vehicles that support them) are collectively known as the strategic triad. But does this three-pronged nuclear strategy still make sense? Joe Kirschbaum, a director in our Defense Capabilities and Management team, led a team that examined this issue. Listen to what they found, and read on as today’s WatchBlog examines the strategic triad.   What exactly is the strategic triad? The strategic triad is made up of three types of strategic delivery vehicles that can launch nuclear weapons. They are

• Nuclear-capable heavy bombers (launched from the air),
• Intercontinental ballistic missiles or ICBMs (launched from the ground), and
• Submarine-launched ballistic missiles (launched from the sea).

Is it still necessary? The United States has maintained the strategic triad while decreasing its number of nuclear weapons. In 1991, the U.S. nuclear weapon stockpile was about 13,000 weapons; as of February 2011, it had fewer than 4,500, according to the Department of Defense. Additionally, the United States signed the New Strategic Arms Reduction Treaty with Russia in April 2010. Known as New START, this treaty requires the United States to further cut its number of strategic delivery vehicles and nuclear warheads by 2018.

(Excerpted from GAO-16-740)

So, as the number of U.S. nuclear weapons and delivery vehicles decreased, DOD assessed whether the nation still needed each type of vehicle. It concluded that maintaining all three parts of the triad was necessary because each vehicle type has specific advantages for nuclear deterrence. These include

• ICBMs can be deployed promptly.
• Nuclear-capable submarines are the most survivable of the three types of vehicles.
• Nuclear-capable bomber planes can be used as a visible show of nuclear force.

Plans for the future DOD and the Department of Energy are planning to invest significant resources to fund and modernize the strategic triad in the coming decades. These agencies projected in 2015 that the costs of maintaining U.S. nuclear forces for fiscal years 2016 through 2025 would total $319.8 billion—and DOD expects that these efforts will extend into the 2030s. We reviewed DOD’s analysis of the strategic triad—for more information, check out the public version of our report.

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• Questions on the content of this post? Contact Joseph W. Kirschbaum at kirschbaumj@gao.gov.
• Comments on GAO’s WatchBlog? Contact blog@gao.gov.