Have nuclear weapons made large-scale militaries irrelevant?

Nuclear weapons have not made large-scale militaries irrelevant. With the exception of North Korea, all other countries have been scaling back their nuclear arsenals over the last 70 years or so. And, most countries, again with the exception of North Korea, would never launch a nuclear weapon for moral reasons. Pre-existing nuclear weapons are now considered old and a large number of military personnel are needed to maintain the nuclear weapons or to help decommission these weapons. In addition, new nuclear weapons are costly, complex and difficult to design and manufacture.

Making weapons grade plutonium or uranium require a specialized technology and precise specifications which in turn requires many military and civilian scientists.