Russia officially suspended it’s participation in the Intermediate-Range Nuclear Forces(INF) on the grounds that US have violated the INF treaty.
US had already withdrawn from the treaty claiming that Russia had secretly developed a missile that violated the INF.
The Intermediate-Range Nuclear Forces(INF) Treaty came into force in 1988. It banned both the Soviet Union(Russia) and the US from developing and deploying land-based cruise and ballistic missiles with ranges between 500 and 5,500 km.However,treaty did not apply to air-or sea-launched missiles.
The agreement was signed to de-escalate tensions as both countries had dozens of such missiles deployed, posing a risk of an accidental nuclear exchange.
Cruise missile is an unmanned self-propelled (till the time of impact) guided vehicle that sustains flight through aerodynamic lift for most of its flight path and whose primary mission is to place an ordnance or special payload on a target.
Ballistic missile follows a ballistic trajectory to deliver one or more warheads on a predetermined target. These weapons are only guided during relatively brief periods of flight—most of their trajectory is unpowered, being governed by gravity and air resistance if in the atmosphere.