If their thinking is that there is no possibility of future nations or pacts of nations threatening the US, then all I have to say is two things. Number one, at a prior point in history they fought a "war to end all wars" and were victorious and then disarmed significantly with this same thought...that didn't work out too well back then.
That really is how the defense officials (most of them, including the ones that count) think these days. They do not see any one really challenging the US for a very long time at sea in any meaningful way, and have become overly enamored with our state of technology and are thus overconfident in its capabilities. They seem to also think that the USn will only fight small, mostly obsolete navies, pirates, and terrorists at sea, and otherwise just show presence or support operations ashore, mainly those in support of the war on terror. For this, should there presumption be true, there would be little justification for a sizeable navy. But, for the reasons you mentioned and others, this is not the case. There are three major or rising powers with large and expanding navies which could potentially challenge us in the future, despite our trade relations, and it is very possible that if they were to challenge us, it would be together as allies. These countries are Russia, China, and India, which on most or all fronts are opposed to the US, and for which the chances of future conflict are considerable. A conflict with them would likely bring us into conflict with many smaller navies as well, and our presence would have to be global. Our current and projected forces are not up to the task of fighting such a large conflict, or even one a bit smaller.
As for the sale, the two are the only ones being offered up. One is to be retained in mothballs indefinitely, and another is to continue its service as the self-defense test ship. The rest are planned to be sunk, although I think one or two may not have had their method of disposal determined, although they are planned to be disposed of. Personally, I think we should maintain the ones remaining in reserve, all of them.
