The US, UK and Russia guaranteed the territorial integrity of Ukraine as part of the "deal" in which Ukraine, then possessing one of the world's largest nuclear arsenals, agreed to give up its weapons of mass destruction.

Can anyone believe that the current situation would exist were Ukraine still to possess even some of those nuclear weapons? Surely the sad result of the current situation is that any nation with - or about to get - nuclear weapons will learn the lesson and refuse to believe the promises of the "big powers" when it comes to nuclear weapons and national security. The agreement appears to be as meaningless (because Russia doesn't honour it and the US/UK are unwilling/unable to sustain it) as Franco-British guarantees to Poland or Czechoslovakia in the 1930s.

Nations around the world will conclude that the only sure way to protect themselves from Big Power aggression would be to possess WMDs. What an appalling outcome for which we've no-one to blame but ourselves.

Professor William G Naphy,

1 Calsayseat Road,

Aberdeen.