It is usually suggested that Stalin agreed to let the Soviet Union join the United Nations when Roosevelt offered him the power of a veto at the Yalta conference in February 1945. One should be wary of such spin, since Stalin had already – at conferences in 1942 and 1943 – been strongly in favour of such an organisation. Even more, we find clear public statements in support of the UN, as with the following from the celebration of the October Revolution in 1944:
Accordingly it is not to be denied that in the future the peace-loving nations may once more find themselves caught off their guard by aggression unless, of course, they work out special measures right now which can avert it.
Well, what means are there to preclude fresh aggression on Germany’s part and, if war should start nevertheless, to stifle it at its very beginning and give it no opportunities to develop into a big war?
There is only one means to this end, apart from the complete disarmament of the aggressor nations: that is to establish a special organization made up of representatives of the peace-loving nations for the defence of peace and safeguarding of security; to put at the disposal of the directing body of this organization the necessary minimum of armed forces required to avert aggression, and to oblige this organization to employ these armed forces without delay if it becomes necessary, to avert or stop aggression, and to punish those guilty of aggression.
This must not be a repetition of the sad memory of the League of Nations, which had neither the right nor the means to avert aggression. It will be a new, special, fully authorized international organization having at its command everything necessary to defend peace and avert new aggression.
Can we expect the actions of this world organization to be sufficiently effective? They will be effective if the great Powers which have borne the brunt of the war against Hitler Germany continue to act in a spirit of unanimity and accord. They will not be effective if this essential condition is violated. (Works, vol. 15, p. 398).