Even though Ukraine is not a member of Nato – and therefore is not covered by the alliance’s mutual defence treaty – the west has signed a series of bilateral agreements with Kiev over the last 20 years in which it has agreed to help protect Ukraine’s territorial integrity.
Given the rapidly escalating events inside Ukraine, such international agreements may seem a mere legal nicety. But many in Ukraine believed the pacts provided the country with a measure of security, and they will still help guide the west’s response to Russian activities.
Perhaps just as importantly, leaders in other capitals in the region who either have or are contemplating similar agreements with the west – be they association agreements with the EU or partnership action plans with Nato – are surely watching to see if these pacts are worth the paper they’re written on.
In the White House’s statement after President Barack Obama’s phone call with his Russian counterpart Vladimir Putin on Saturday, Washington referred to several of those agreements, starting with the so-called “Budapest Memorandum”. Here’s a quick primer on the international texts that govern the west’s – and, in many cases, Russia’s – relations with Ukraine.