The Last Nuclear Arms TreatyPranay Vaddi, Nicholas Blanchette, and Garrett Hinck

New START is the final linchpin of U.S.-Russian nuclear arms control. If the treaty isn’t extended, Washington’s and Moscow’s nuclear arsenals will be wholly unconstrained for the first time in decades.

Why New START Matters

New START is the only nuclear arms control treaty left between the United States and Russia. But it expires on February 5, 2021, unless extended by up to five years.

Without it, there will be no limits on—or transparency into—the size and composition of the U.S. and Russian nuclear arsenals.

What New START Does

Essentially, the treaty:

caps each country at 1,550 deployed long-range nuclear warheads

restricts each side to 700 deployed long-range nuclear delivery vehicles

limits each country to 800 deployed and nondeployed launchers and delivery vehicles.

Long-range nuclear delivery systems include:

land-based intercontinental ballistic missiles (ICBMs)
submarine-launched ballistic missiles (SLBMs)
heavy bombers equipped to carry nuclear weapons

New START does not attempt to limit:

nondeployed, stockpiled nuclear warheads

research and development, or testing of new nuclear weapons and delivery systems

current missile defense programs

or conventional weapons (not based on missiles, bombers, or submarines restricted by the treaty)

Who’s Got What

The treaty gives each side flexibility to decide the mix of nuclear weapons and delivery systems it wants to deploy.

United States*:

656 deployed long-range ICBMs, SLBMs, and heavy bombers

1,365 long-range nuclear warheads on deployed nuclear delivery systems

800 deployed and nondeployed launchers of ICBMs, SLBMs, and heavy bombers


524 deployed long-range ICBMs, SLBMs, and heavy bombers

1,461 long-range nuclear warheads on deployed nuclear delivery systems

760 deployed and nondeployed launchers of ICBMs, SLBMs, and heavy bombers

* Data is accurate as of March 2019.

How to Make Sure Neither Side Cheats

The United States and Russia can each carry out up to eighteen short-notice, on-site inspections of each other’s nuclear bases and support facilities annually. Inspectors check the location of nuclear weapons, their deployment status, and the production of new ballistic missiles. This includes inspecting ballistic missiles and bombers to ensure the number of warheads they were declared to be carrying is accurate.

306on-site inspections have been carried out since New START took effect.

Why Criticisms of New START Are Misplaced

Failing to extend New START would not solve common complaints about the treaty and would create or compound other national security risks as well.

Claim: Russia is developing new nuclear weapons that will not be limited by New START.


Claim: China is not included in the treaty, so the United States is handcuffing itself.


Claim: The treaty does not limit Russia’s shorter-range nuclear systems.


Claim: Russia has cheated arms control rules.


What Happens If the Treaty Ends

More Nuclear Weapons Without the treaty’s limits, Russia will be able to build and deploy more nuclear weapons targeting the United States. Both sides could get sucked into a dangerous arms race.

An Information Gap Under the treaty, Russia shares information about its nuclear arsenal and allow inspections. Without this information, U.S. intelligence would have to pull resources from other missions and would still have a less complete picture of Russia’s nuclear weapons, raising the risk of miscalculations.

Ballooning Costs The costs for U.S. nuclear weapons modernization, sustainment, and related infrastructure are already pegged at nearly $1.2 trillion over the next thirty years—and this is assuming New START stays in force. If the treaty ends, Washington and Moscow may enter a new arms race, creating even greater costs.

Undermining Future Agreements Arms control has been a progression of one treaty to the next. If New START expires with no replacement, it will leave the United States and Russia without a common starting point for future efforts.

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