The US Walks Away From the Intermediate Missile Treaty

The 1972 ABM or anti-ballistic missile treaty the US walked away from that in 2001 early 2002 and this was often seen as the cornerstone of the yarps. It's very easy to overwhelm defensive systems either by putting multiple warheads on your existing missiles or simply fake devices that can be deployed even balloons. The Russians were strongly opposed to the withdrawal from this treaty but the US thought they could somehow come up with mechanisms to really defend which initiated a lot of an arms war.