As U.S. relations with Russia go from bad to worse, even old agreements seem at risk. Such as the Intermediate-Range and Shorter-Range Missiles, or INF (Intermediate-Range Nuclear Forces) Treaty.

The 1987 pact essentially cleared Europe of mid-range missiles (between 500 and 5500 kilometers). But the State Department recently charged Moscow with violating the treaty. Russia disputes the claim and responded with accusations of U.S. violations.