A Cold War treaty is unravelling but can it be rescued? | Inside Story

Treaties are hard fought and often take years to negotiate.

They are designed to keep peace, preventing rival countries from going to war.

One agreement, signed in 1990 towards the end of the Cold War, is the Treaty on Conventional Armed Forces in Europe.

The United States, other NATO members, the former Soviet Union and its central and eastern European allies agreed to prevent military build-up at their borders.

But in recent years, NATO's expansion towards east and Russia's security interests have left that accord all but meaningless.