Proving the source of a cyberattack is difficult but all the forensic evidence points toward Russian intelligence agencies as the perpetrators of the theft of the national committee emails, given the close similarities between this attack and previous Russian cyberoperations. It is less clear who gave the emails to WikiLeaks, but the same agencies are the prime suspects. Whether the leaks were ordered by Mr. Putin, or just designed by apparatchiks who thought it might please him, is anyone’s guess. On Sunday morning, the issue erupted, as Mrs. Clinton’s campaign manager, Robby Mook, argued on ABC’s “This Week” that the emails were leaked “by the Russians for the purpose of helping Donald Trump” citing “experts” but offering no other evidence. So why would Putin want to support Donald Trump for President? Mook suggests that the Russians might have good reason to support Trump because of Trump's views on NATO: The Republican nominee indicated in an interview with The New York Times that he might not back NATO nations if they came under attack from Russia — unless he was first convinced that the counties had made sufficient contributions to the Atlantic alliance.