Trump’s military doctrine has been difficult to discern, but it is sharpening into focus. Strategically, he favors isolationism in the mode of Republican Senator Rand Paul and Democratic Representative Tulsi Gabbard. When forced to deploy, he prefers weak enemies like the Islamic State, and for long-term deployments, he prefers to commit to worthless, uncontested objectives, like the meager and wrecked oil fields of Syria. He favors extremely lax rules of engagement. Even repeated, planned acts contrary to the letter and spirit of military law and ethical codes are forgiven, and his warfighters are unconstrained by modern laws of armed conflict.
You might call this program a form of deregulation, parallel to the deregulation he has pushed in other sectors, including environmental protection and finance. Deregulation is much stupider in war than it is in those other fields. If you deregulate polluters, you may end up poisoning the environment—but at least the environment is inanimate, and does not arm itself reciprocally, to match the violence you freed yourself to commit against it. Battlefield enemies are different. ISIS is already willing to commit atrocities against Americans, but now more scrupulous rivals of the United States can reasonably infer that if they fight us according to the laws of armed conflict, they are suckers. One reason more than 80 countries allied to fight ISIS is that they flagrantly ignored these laws. Now we do too.