Rove suggests that either the President set out to mislead, or he lacked experience to such a degree that he didn't anticipate the multitude of shifts he would have to make.
I suspect it's a bit of both: Inexperience and naivete when it came to foreign policy, coupled with a clear understanding that his left-wing domestic instincts would have been soundly repudiated by the electorate had he voiced them before being elected.
In any case, what's most interesting is the fact that, in little more than 100 days, the President has managed to betray both constituencies who elected him: (Thankfully), the loony left, on its agenda of undermining the US's national security, and then regular Americans, who wanted a President who would restore America's economic strength and encourage success and free enterprise, rather than stifling them.
At some point, all that betrayal catches up with you. As Jack Kelly points out, theprocess may already be underway.