Maybe, though the military has studied similar ideas before and nothing has ever come from it, so I'm sceptical they're going to throw the kind of funding at it that would be required here. As a general concern, actual travel time doesn't usually seem to be the main determinant of how fast military forces can be deployed.

But who knows. The idea of a big capsule coming down in a war zone and a bunch of tanks and marines rolling out certainly seems pretty cool, and I'm sure Musk and his lobbyists will at least try and convince the DoD that its something worth throwing a lot of $$ at.