In 1987, President Ronald Reagan and the last Soviet leader, Mikhail Gorbachev, signed the Intermediate-Range Nuclear Forces Treaty — a document widely known today as simply the INF treaty. The breadth of the treaty pertained to ground-launched, medium-range missiles that could engage targets between 300 and 3,400 miles away. It was part of a broader focus on reducing nuclear stockpiles, but notably, the treaty included both nuclear and conventional medium-range platforms. It ordered both nations to destroy their current stockpiles of such weapons and barred them pursuing the development of, or conducting tests with, any such platform in the future.

Just a few years later, as the Soviet Union fell, the United States was able to maintain the treaty with the newly formed Russia as well as a few former Soviet territories turned newly born nations like Ukraine, Belarus and Kazakhstan.

The United States first publicly announced that they had intelligence confirming Russia’s violation of the treaty in 2014, saying that Putin’s regime had specifically violated the sections pertaining to the testing and development of such a platform. However, the American government declined to provide any more information, likely because doing so may have revealed elements of the nation’s intelligence gathering apparatus. However, in December of last year, the American government once again delivered public accusations of INF treaty violations, but this time they went so far as to call the platform out by name.

Russia’s 9M729 cruise missile (which carries the NATO designator SSC-8) is a land-based platform that experts assess to have an operational range of 310 miles to 3,400 miles. A report released by the State Department that same month wasn’t much more specific of about Russia’s violations of the treaty, but did also point out that the Russian military was no longer honoring the specifics outlined within it.