Activists wear masks of President Trump and Russian President Vladimir Putin as they arm-wrestle during a demonstration Thursday in front of the U.S. Embassy in Berlin against the ending of the Intermediate-Range Nuclear Forces Treaty. (Omer Messinger/EPA-EFE/Shutterstock)

Editor’s note: In light of the U.S. statement Friday, we asked James J. Cameron to update his earlier analysis on the INF Treaty.

On Friday, Secretary of State Mike Pompeo announced the U.S. withdrawal from the Intermediate-Range Nuclear Forces (INF) Treaty. What does the U.S. move mean? Here are five things to consider:

1. What is the INF Treaty?

The INF Treaty was signed in December 1987 by President Ronald Reagan and Soviet General Secretary Mikhail Gorbachev. It prohibited the United States and the Soviet Union from possessing, testing and deploying ground-launched cruise and ballistic missiles with ranges between 300 and 3,400 miles.

Under the treaty, Washington and Moscow destroyed 846 and 1,846 missiles, respectively. Given their relatively limited range, these systems were designed chiefly to fight a theater nuclear war in Europe. Short flight times and unpredictable flight patterns made these missiles hard to detect, so strategists argued that these systems exacerbated crisis instability and increased the chances of accidental nuclear war. European countries, therefore, considered the destruction of these missiles highly beneficial to regional security.

Despite its name, the INF Treaty covered all types of ground-launched cruise and ballistic missiles — whether their payload is conventional or nuclear. Moscow and Washington are prohibited from deploying these missiles anywhere in the world, not just in Europe. However, the treaty only applies to ground-launched systems. Both sides are free to deploy air- and sea-launched missiles within the 300- to 3,400-mile range.

2. Has Russia violated the treaty?

The State Department first declared that Moscow had violated the treaty in July 2014. U.S. officials have since identified the 9M729 cruise missile as their main concern. Outgoing Director of National Intelligence Daniel Coats told reporters more recently that Russia had tested the 9M729 in a way that “appeared purposefully designed to disguise the true nature of their testing activity.” The United States has not released an assessment, but military analysts think the missile has a range of about 1,250 miles.

In February 2017, U.S. officials said they thought Russia had deployed the system operationally. The United States has pursued an increasingly robust policy, including sanctions, to pressure Moscow back into compliance with the treaty.

Moscow denied the treaty violation, demanded to see the evidence and responded with its own list of alleged U.S. infractions, as well as the exhibition of a launch tube that it claimed was that of the 9M729. However, it has provided no substantive rebuttal of U.S. accusations.

The United States has not published the supporting intelligence, so it is impossible to fully verify officials’ claims. However, as NATO allies have learned more, their position has become more closely aligned with that of Washington. At their summit in July 2018, NATO leaders stated that a Russian violation is “the most plausible assessment” of the available evidence.

3. Where does China fit in?

In his October 2018 announcement of plans to withdraw, Trump criticized the INF Treaty for not restraining the buildup of Chinese forces. China is not bound by the INF Treaty and has deployed intermediate-range missiles in significant numbers. U.S. Ambassador to South Korea Harry Harris, the former head of U.S. Pacific Command, estimates that intermediate-range systems make up “approximately 95 percent” of the People’s Liberation Army missile force.

Some observers have argued that the INF Treaty is anachronistically “Eurocentric,” failing to take into account the U.S.-Chinese military balance — which is becoming increasingly central to Washington’s strategic calculations. It would be far cheaper for the United States to deploy ground-based systems in Asia, rather than to position them on small and expensive sea- and air-based platforms.

However, Washington has few bases in the Pacific where it could place a ground-launched missile within range of China, without consent from allies. It is an open question whether Japan, South Korea or Australia would be willing to host such systems.

4. What are the military implications of withdrawal?

The United States has no operational systems similar to the Russian missile, but a number are in the works. A ground-launched version of the Tomahawk cruise missile will take about 18 months to deploy, while an intermediate-range ballistic missile will require at least five years to develop. The U.S. Army is preparing tests of a new Precision Strike Missile that could be in the INF range, but that will not be ready until 2023.

Moscow is in a very different position and could rapidly expand deployment. Moscow has been deploying the 9M729 at a low but steady rate. Released from its official obligations under the treaty, Russia could deploy units more rapidly.

Russia could also effectively reclassify the RS-26 “Rubezh,” an experimental system that has been tested just above the INF Treaty’s 5,500-kilometer limit. To avoid violating the INF, Russian officials previously described the RS-26 as an intercontinental ballistic missile. However, it could form the basis for a missile of a slightly shorter range if Moscow wished to boost its INF forces — without counting it under the U.S.-Russian New START accord governing longer-range systems.

5. What are the diplomatic implications of withdrawal?

The INF withdrawal issue has been controversial with U.S. allies, further straining the NATO alliance at a difficult time for transatlantic relations. NATO had favored a policy designed to push Moscow back into compliance. It has pledged to respond to the INF Treaty’s demise, but the nature of that response is uncertain.

It is unlikely that NATO allies will agree to host U.S. intermediate-range systems on their territory, a move some fear would lead to a new arms race in Europe. German Foreign Minister Heiko Maas has been the most vocal in opposing new deployments, while Poland — traditionally more hawkish on Russia — has stated that any such move would require unanimity within the alliance.

Withdrawal will probably not lead to a new INF deal binding the United States, Russia and China. China has rejected the U.S. offer of trilateral arms control talks. Moscow and Washington engaged in strategic stability discussions this year, but as yet nothing substantive has emerged.

The collapse of the INF Treaty leaves New START, governing strategic weapons, as the only U.S.-Russia nuclear arms control deal still standing. But national security adviser John Bolton’s recent comments criticizing New START as “flawed from the beginning” suggest that the Trump administration is unlikely to extend it past its expiration date of 2021. In the absence of new accords, the five-decade-old U.S.-Russian nuclear arms control regime will meet its demise.

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Cameron is a postdoctoral research associate in the Department of War Studies at King’s College London. He is the author of “The Double Game: The Demise of America’s First Missile Defense System and the Rise of Strategic Arms Limitation” (Oxford University Press, 2017).” Follow @cameronjjj.