War on terror

First Big Test for Mattis: Pitch Plans to Fight ISIS and Not Alienate Trump

As Defense Secretary Jim Mattis prepares to submit his first big pitch to his new boss — options for accelerating the fight against the Islamic State — he is balancing the need to rein in President Trump’s more extreme impulses without distancing himself too much and losing White House favor.

Mr. Mattis, a retired Marine general, has already assumed an outsize role in the administration — part valued aide to the new president, who has quickly come to adore him, and part reassurer in chief to global leaders, who cling to his every utterance in the hope that he will help keep the White House from undoing decades of national security policy.

Nowhere is this juggling act clearer than in the decisions confronting Mr. Mattis about speeding the fight against the Islamic State. Mr. Trump made that fight a centerpiece of his national security strategy during the campaign, saying he would give his generals 30 days to produce a plan to defeat the group, and he has urged an alliance with Russia to combat the militants in Syria. But such a move is anathema to Mr. Mattis, who has said repeatedly that he does not view Russia as a trustworthy partner.