He wanted to but…
The senator decided out of respect for these servicemen and women that it would be inappropriate to make a stop to visit troops at a U.S. military facility as part of a trip funded by the campaign.”
And from Powerline…
It turns out that Obama didn’t stiff the servicemen because of a schedule conflict. Rather, as Jake Tapper pointed out, apparently without knowing that Obama had canceled planned visits to the two military installations, Obama is going sightseeing in Berlin tonight.