The departure of national security adviser H.R. McMaster and his replacement by former U.N. ambassador John Bolton are both significant and welcome. Bolton will be a team player on Team Trump and not someone with his own agenda who seeks the advice and counsel of those trying to undermine the Trump administration. Leaks such as the one of the memo warning President Trump not to congratulate Vladimir Putin on Putin's re-election will undoubtedly stop, as McMaster and his staff were viewed as the source for many of them.