Answer:
Nationalists call for total security of their own country for themselves, typically with whatever is the most powerful. In this case, nationalists would want the development of nuclear weapons, as it gives them the option to use the policy of deterrence, and could give them a bigger voice within the world community to push for what they want nationally.
The best examples of this are the "original" nuclear superpowers, which is the United States and Russia (antea quae Union of Soviet Socialist Republics (U.S.S.R.)). They both enjoyed original power within foreign influences. With the fall of the U.S.S.R. and the United States becoming the World's only superpower, the U.S. continued to enjoy trade benefits, the ability to hedge the U.S. currency as the global currency to trade against, and having the largest voice in world affairs (which is bolstered by a large network of alliances).
As such, countries that have typically been unfriendly (to say the least), with each other, would try to race to obtain the most powerful weapons in hope to use it to sway the other side to come to a more favorable agreement towards the host country. However, it is worth noting that many already nuclear-owning countries have been trying to limit the amount of nuclear weapons in the world (Through the SALT treaties and the modernized versions), and tries to suppress the other nations from being able to develop and acquire such weapons.