The Porton Down laboratory near Salisbury was evidently somehow involved in the Skripal case, though it is unclear to what extent this was a “news game” between MI5 and Russia’s SVR.
In October 2018, US President Donald Trump stated that the US would withdraw from the INF treaty due to Moscow’s violations of its commitments. However, the US didn’t provide any proof to support this claim.
In July 2014, President Obama officially accused Russia of testing an intermediate-range land-launched missile in violation of the INF. Russia’s violations were also acknowledged by NATO Foreign Ministers in a meeting in Brussels on 4 December 2018. NATO allies share the US government’s assessment that Russia has developed and fielded a missile system, the 9M729, which violates the INF Treaty and poses significant risks to Euro-Atlantic security. The US gathered detailed information on Russia’s flight-testing of the 9M792 missile to distances well over 500 kilometers, in violation of the INF, and provided Moscow with evidence about the 9M729’s violations, including geographic coordinates and dates for the tests. Russia has continually denied any wrongdoing.
In a statement released on 1 February 2019, the North Atlantic Council noted that Russia had “taken no demonstrable steps toward returning to full and verifiable compliance” and that “Russia will bear sole responsibility for the end of the Treaty.”
In February 2019, the US suspended its participation in the INF Treaty, stressing that nearly 6 years of diplomacy and more than 30 meetings have failed to convince Russia to return to compliance with the INF Treaty. On 3 July 2019, Russian President Vladimir Putin signed a federal law on the suspension of the INF Treaty. On 5 July 2019, the Russia-NATO Council was held, following which Secretary-General of the Alliance, Jens Stoltenberg, said that NATO and the Kremlin have fundamental differences in this matter.
More disinformation cases on the INF treaty can be found here.