The US is poised to begin pulling out of one of the world’s most important nuclear treaties. Secretary of State Mike Pompeo is expected to announce today that the US will stop participating in the Intermediate-Range Nuclear Forces Treaty with Russia, according to two US officials and multiple diplomatic sources. This would be a stunning development because the 1987 treaty has been a centerpiece of European security since the Cold War. The US and European allies have maintained for years that the Russians are violating the agreement. But if the US does indeed drop out of the treaty, fears of a new nuclear arms race with Russia ramp up considerably.