Mattis swipes at Trump, warns of ‘storm clouds gathering’ amid fractured alliances

Former Defense Secretary Jim Mattis took several implicit swipes at President Trump’s leadership in an op-ed published Wednesday, warning about the fallout from fractured alliances and increasing divisiveness under the current administration.

Mattis’ comments were included in a lengthy essay adapted from a forthcoming book and published in The Wall Street Journal. They amount to the most extensive remarks from him about his time in the Trump administration since he quietly resigned in January.

In the essay, Mattis suggested he left his post as secretary of defense amid concerns about...