Though he extended US military action in Syria and Iraq during his first year in office, Trump has been a loud sceptic of American military ventures.
He now is vowing to pull out of Syria, and he had to be talked out of pulling the plug on Afghanistan.
What's more, any move by Trump to launch an unprovoked attack on either Iran or North Korea will run into a wall of opposition from US allies, Congress, Defence Secretary Jim Mattis and the Pentagon brass, and, most likely, Trump's own political base, which has grown used to cheering his rhetoric about wasteful wars.
War would also be a break from the emerging diplomatic model of this President, which is to bluster and bluff, then cut a deal.
That's what happened last week with South Korea, which saw the free-trade agreement Trump called "horrible" not torn up but slightly amended.
Trump has been trying to do the same with the Iran pact, denouncing it while his diplomats quietly pressure European governments to agree to fixes - a process that, at least until the ouster of Rex Tillerson from the State Department, looked as though it might succeed.
The main danger, then, is not that Trump will choose war.
It is that he will stumble into it, through impulsive acts unattached to any coherent strategy.
He has set up two big, high-risk decision points for this spring: on whether to renew sanctions on Iran in mid-May and whether to deal with North Korea's Kim Jong Un at a summit by the end of that month.
If he accepts a face-saving bargain on Iran with the Europeans, or a promise by Kim to denuclearise, he will contradict everything that the notoriously inflexible Bolton has stood for over decades - raising the question of why Trump hired him.
If, on the other hand, Trump takes the counsel his new aide has already offered on television and scraps the Iran accord while stiffing or rebuking Kim, he will create two crises - and hand the initiative in both to America's enemies.
Iran's clerical regime will be particularly pleased.
The nuclear accord has been a big disappointment in Tehran: The investment it was supposed to trigger from Western companies has mostly failed to arrive, and a stagnating economy is fuelling popular unrest.
Trump could give President Hassan Rouhani a chance to split the United States from Europe by demanding new concessions from the latter in exchange for sticking to the deal.
Or the Revolutionary Guard Corps could use the militias it controls in Iraq and Syria to bleed US forces with ambushes and roadside bombs, as it did a decade ago.
Or, Supreme Leader Ayatollah Ali Khamenei could roll the dice and resume uranium enrichment, betting that Trump won't have the nerve or the political support to stop it with military action.
It's pretty evident that Trump hasn't thought much about what happens after he tears up the deal - he's simply fixated on undoing the legacy of President Barack Obama.
He doesn't have a strategy for containing an aggressive Iranian response. But Bolton, the ruling princes of Saudi Arabia and the United Arab Emirates, and perhaps Israel's Benjamin Netanyahu will push the White House for military action. Trump may find himself cornered.
Something similar could happen in North Korea.
If Trump fails to satisfy Kim's demands for concessions, the predictable result is a resumption of the regime's tests of intercontinental missiles and nuclear warheads.
Then what?
Trump doesn't have a plan, but Bolton has already announced his - a unilateral US strike, followed by the occupation of North Korea by US troops.
Trump may manage to avoid these crises while still achieving his underlying aim of monopolising the world's attention.
He could accept Europe's offer on Iran, or give the deal another extension to leave time for more negotiations.
He could announce a grand-sounding but vague accord with Kim, delegating the substance to years of tedious but time-buying negotiations.
That's exactly the sort of temporising that Bolton has described as worse than going to war.
But he may learn, as numerous Trump aides already have, that Trump is in charge of this reality show.
