I realize that the impulse is to doubt everything said by Clinton or one of her appointees, and that's a very healthy and good impulse. It will serve you well. But this time, the guy is right. Wikileaks is a Russian intelligence project. Russia Today, which has been leading the broadcasting of this story, is openly Russian propaganda.
Doubtless Putin takes Trump's outspoken pragmatism about NATO to be a good sign for Russian interests. No one really doubts that everyone would be pragmatic in fact, but the secret in diplomacy is you're supposed to pretend that you would be principled instead. This is an old story.
Hillary Clinton, being a former Secretary of State, understands the rules and is playing accordingly. This has led to the highly amusing spectacle of her supporters, many of whom would disband the nuclear forces entirely if they had their druthers, arguing for a week about how important it is to have a strong deterrent against Russian aggression. They are no more serious about nuking Russia than she is, but they're all pretending they are.
The fact is that President Obama has weakened the United States' global position so much that the next president will have no choice but retrenchment. Some concessions will have to be made to Russia, to China, and possibly even to Iran. Clinton will make those concessions if elected in terms of conceding American power to 'international' institutions that happen to favor Russian or Chinese interests -- things like the TPP, which she will of course resume supporting once she's elected (as her VP choice does as well, I notice). Trump, on the other hand, will negotiate some sort of deal directly.
Either way, America's standing in the world will diminish, at least for a time. Even the most hawkish president would have no choice but to drop back and try to figure out what new lines are tenable.