A treaty signed in 1994 by the US and Britain could pull both countries into a war to protect Ukraine if Putin's troops intervene. The Budapest Memorandum was signed by Bill Clinton, John Major, Boris Yeltsin and Leonid Kuchma – the then-rulers of the USA, UK, Russia and Ukraine - as part of the denuclearization of former Soviet republics after the dissolution of the Soviet Union Technically it means that if Russia has invaded Ukraine then it would be difficult for the US and Britain to avoid going to war. ... the [Budapest] Memorandum is legally binding.' It promises to...