Leadership Lesson: We should consider everything that makes up our leaders — and which will probably contribute to our own legacy — so we’re not just loyal to our leaders’ loyalty to our own priorities.

So General James Mattis, our country’s latest Secretary of Defense, has had enough.

He has tendered his letter of resignation, effective a few months from now, stating the President would be best served by a Secretary whose military and diplomatic vision are “better aligned” with his own.

And, based on the actions the president wants to take without consulting his Secretary — drawing down troops in both Syria and Afghanistan —…