Well, yes. 0bama wasn't very good at it and Trump doesn't intend to do it. Only five of the 28 members of NATO have lived up to their pledges in terms of military spending and all of this blather about an "independent" Europe ignores two things: they couldn't operate independently if they wanted to, especially if Britain does BREXIT, and they're so energy dependent on Russia that they couldn't continue it if they started. So what's even up for discussion here?
The days of "we believe in equality when it comes to an equal vote, but we don't believe in equality when it comes to contributions" are over. That European leaders supposedly experienced and sophisticated in matters diplomatic would fall for, and defend, the travesty that is the Iran "treaty" doesn't argue very strongly in favor of them standing up for themselves even if they are willing to develop the wherewithal. Blaming Trump for all this is flogging the messenger.
IIRC we had to lead from behind in Libya because they didn’t even have refueling capability for their planes.