Robert Merry praises a warmonger

Robert W. Merry, in his op-ed contribution to the Sunday New York Times, praises James K. Polk as one of the great American presidents. This is what Merry has to say about the Mexican War, a classic example of an insidious and unnecessary acts of expansionist military aggression by one nation against another:

In the end, he [Polk] succeeded in all four goals and annexed Texas along the way, thus expanding the United States by a third and creating a transcontinental nation positioned to dominate two oceans. In doing all that, he accomplished what the American people wanted him to do and won the respect of future historians.

I wonder what "future historians" he is referring to (apparently himself, as the author of a book on Polk). I remember once taking a narrated bus tour through Mexico City and hearing the recorded voice referring to the Mexican War as the "1847 North American invasion." Mexicans today understand what Abraham Lincoln (who opposed the Mexican War) and Henry David Thoreau (who also opposed it) understood back then--the war was an unjustifiable act and the pretext for a land grab. This apparently does not seem to bother Merry, who thinks that as long as Polk was successful at achieving his goal of expansionism then he counts as having been a "great" President. His standards of what constitutes "greatness" are a little different than my own.