Well, in the unlikely event Trump does get the nomination, he certainly needs someone who is smart on national security because Trump is downright ignorant on the subject:
Question: Of the three legs of the triad, though, do you have a priority?
Trump: I think, I think, for me, nuclear is just the power, the devastation is very important to me.
Trump is clearly not someone ready to be commander in chief.
Two things stand out from this. First of all, it shows Trump was totally checked out from national affairs during the 70s and 80s. Secondly, it is revealing that the press did not eviscerate Trump for this. If any other Republican candidate had given such a stupid answer, the press would have kept it on the front page for weeks. But Trump got a free pass. Instead, the front page is reserved for Cruz and his accurate comments on New York values (as told by Donald Trump). One would think that the press actually wants Trump to be the GOP nominee.