Although i certainly find universal nuclear disarmament to be a morally correct and honourable goal, it's also very clear that a reasonable part of those campaigning for it are very entrenched in anti-communist views - focusing with much strictness on the development of nuclear warheads by the DPRK, China and Russia (which isn't socialist, but nevertheless). At best they criticize the gigantic war industry of the US, but only by liberal metrics of "we should only have the necessary" and stuff like that.
However, it is also clear that the development of nuclear armament - although not the main priority - should, very clearly, be something that socialist states now and in the future must consider. Even if not full blown nuclear armament - at least ICBMs and others like it. For it is not a mistake or an insanity that the DPRK, for example, has developed nuclear warheads; it knows that it is the subject of constant international harassment and it is prepared to have what is, for now, the most powerful rhetorical weapon against this. Future socialist countries should, yes, follow this!
And, you see, a big number of communists mainly in the West (and to great extents elsewhere) do not see military strategy and development post-revolution as important. And this is stupid! Foolish! Russia was the subject of an inter-imperialist gangbang from all sides, and it only survived to form the Soviet Union with the development of a strong, renewed Red Army, big in bulk and in equipment. And socialist revolutions in the future will also need to have this: they'll need a Red Army, Red Navy and Red Air Force. And communists NOW should think about how this needs to be developed and need to learn strategy and need to be active within military circles (although, of course, in the imperial core the military is a much clearer peon of international capital than in the global south, so things are harder in this stance).
Socialism here, now and in the future will certainly be striked with the combined forces of capital tumbling down on any form of organized proletariat. This happens to countries contrary to the imperialist USAmerican order, socialist or not: it imposed a military dictatorship in Cambodia in 1970, it couped Chile in 1973, it annihilated Grenada in 1983, it helped oust Aristide in Haiti in 2004, it destroyed Libya in 2011 - not counting many others. This means that developing a strong, truly proletarian armed force and developing means to defend it long term beyond that - ICBMs, and, of course, following the correct Korean path, even nuclear missiles - are crucial for the establishment of socialist states. And only when socialism is triumphant or on its way to triumph may these rhetorical and physical defenses of socialism be dismantled. Or only if the capitalist world surrenders all of it at the same time. However, believe me: they won't.
As such, i'd say that in the 21st century, Lenin's little formula can be adapted to: Communism is Soviet power + electrification + ballistic missiles, in a gross simplification. The basis, the development and the defense.