The signing of the Budapest Memorandum on December 5, 1994, between the then Presidents of Ukraine and Russia, Victor Yuschenko and Boris Yeltsin respectively.
In it Russia guaranteed to protect the territorial integrity of Ukraine in return for their giving up the nuclear arsenal left over from the Soviet Union.
Today Putin celebrated the anniversary of the Budapest Memorandum by firing 70 missiles on Ukrainian cities targeting their residential areas, power grid and water pumping stations.