From the Document: "On August 2, 2019, the United States withdrew from the Intermediate-Range Nuclear Forces (INF) Treaty. It had notified Russia of its intent to withdraw on February 2, 2019, and, consistent with Article XV of the treaty, the withdrawal took effect six months later. The United States withdrew from the treaty in response to Russia's deployment of an INF-range ground-launched cruise missile, which violated the treaty's ban on missiles with a range between 500 and 5,500 kilometers."
CRS In Focus, IF11051
Congressional Research Service: https://crsreports.congress.gov/