Answer : 1. "Russia"
Explanation :

Solution: Russia has officially withdrawn from international security agreements banning the use of conventional weapons, saying that NATO expansion has made such cooperation impossible. NATO announced it was formally suspending a key Cold War-era security treaty in response to Russia's exit from the accord. Most of NATO's 31 allies signed the Treaty on Conventional Armed Forces in Europe, aimed at preventing Cold War rivals from amassing forces on or near their mutual borders. It was signed in November 1990.