What is the INF Treaty?
The Intermediate-Range Nuclear Forces Treaty, or INF treaty, bans Russia and the United States from possessing, producing or conducting test flights of ground-launched cruise missiles and ballistic missiles with a range of 500 to 5,500 kilometers (310 to 3,420 miles). It allows sea-based and air-delivered missiles at those ranges as well as research and development of ground-launched systems.
How did the treaty come about?
The 1987 treaty was signed between President Ronald Reagan and Soviet leader Mikhail Gorbachev. By the time it was implemented in 1991 an entire class of conventional and nuclear-capable missile systems had been destroyed, boosting security at the end of the Cold War. It remained in force after the collapse of the Soviet Union in 1991.
Why is the Trump administration threatening to pull out?
In October 2018, President Donald Trump announced the United States' intention to exit the INF treaty due to Russian noncompliance. He also suggested the United States should renegotiate the treaty to include China, considered by US strategists the primary long-term challenger to American power.
In early December, the US State Department declared Russia in breach of the INF's terms and began a 60-day period for Russia to comply, otherwise the United States would notify parties to the treaty of its intention to withdrawal by February 2. Under the terms of the treaty, a formal US withdrawal takes effect six-months after notification.
The Trump administration's claims of a treaty violation are not new. In 2014, the Obama administration formally accused Moscow of producing and testing a new ground-launched cruise missile in violation of the treaty.
Officials in Trump administration later publicly identified it as the 9M729 missile, or NATO-designated SSC-8, with a range of over 500 kilometers in violation of the treaty. Russia was also accused in 2017 of actually deploying the missile system.
Repeated meetings between Moscow and Washington have failed to address treaty compliance issues.
What does Russia say?
The Russians claim the 9M729 has a range of 480 kilometers and thus falls within what is allowed under the INF treaty. Russia has consistently denied it was breaching the agreement, instead raising a number of concerns over Washington's compliance with the treaty.
The main accusation relates to the United States deploying the ground-based Aegis anti-missile system in Europe, something Washington has refuted by arguing it is a non-offensive, anti-ballistic missile defense system.
Russia argues the NATO-backed system which it views as a threat can also fire offensive cruise missiles and has many of the characteristics of INF treaty prohibited missile systems. Moscow has also raised the issue of some US drones that it claims are equivalent to a ground-launched cruise missile.
Russia has also long complained that it is bound by the treaty while China, India, Pakistan and Iran are not.
What about China?
China has risen to become a major economic, political and military power since the INF treaty was drawn up in the 1980s as a bi-lateral US-Soviet treaty. Some US strategists argue that by not including China, the INF treaty allows Beijing to develop a conventional missile advantage and limits the US ability to counter this threat.
In principle Russia is open to including China in a new treaty that would allow Moscow to also address its concerns about US missile systems in Europe. However, including China is complicated not only by the nature of arms control talks, but also because Beijing would likely also want to include nuclear-armed India. India, in turn, would want limitations on its rival, nuclear-armed Pakistan.
Why does this all matter?
Land-based missile systems today provide only a marginal capability, unlike during the potential conflict scenarios during the 1970s and 80s. Both Russia and the United States are already allowed to possess sea and air-launched missiles at INF range that could cover similar targets as land-based systems.
Nonetheless, the collapse of the INF treaty has spawned worries that it could lead to an expensive arms build-up in Europe that could cause divisions within NATO over hosting such systems. Even if the United States wanted to deploy land-based intermediate-range missiles in Europe, there is little political appetite among European countries to host them, let alone a nuclear-capable system. Sowing divisions within NATO would benefit Russia.
More importantly, the collapse of the INF treaty undermines confidence in arms control and non-proliferation regimes in general.
That could be significant as the US and Russia negotiate a follow up to the 2010 New Strategic Arms Reduction Treaty. That strategic nuclear missile arms control agreement must be extended through US-Russia agreement by the treaty's expiry in 2021.