Most experts agree that President Donald Trump’s foreign policy and national security strategy have been disappointing so far, if not disastrous. But historians also know that this isn’t entirely surprising. Since the United States became a global power after World War II, most administrations experienced difficulties getting started. Some — like Ronald Reagan — entered office with a real sense of strategy but floundered at the outset because of bureaucratic infighting or slow staffing. Others — like John F. Kennedy and Bill Clinton — disdained strategy and sought to improvise, and they suffered.

Studies my colleagues and I have conducted at the University of Virginia’s Miller Center demonstrate that administrations typically flounder during their first year. That’s because presidents often focused on domestic policy and resisted efforts to think through a comprehensive national security strategy. Sometimes, presidents selected able leaders to head key departments and agencies but these appointees had trouble collaborating with one another. In other administrations, presidents have disregarded the importance of process or ignored linking foreign policy making to budgetary planning. Often, they failed to nurture allies in Congress and, in recent decades, have been slow to staff key agencies.

Despite their difficult beginnings, many administrations go on to gain their footing and experience real accomplishment in foreign policy. So there is still hope for Trump. But it’s important to first understand that he isn’t just repeating all the early errors that beleaguered his predecessors — he is magnifying them in unprecedented fashion.

First, he has no strategy. Consider the “America First Foreign Policy” that is outlined on the White House website, which appears to be the official expression of Trump’s nationalist populist foreign-policy vision. The Trump administration is “focused on American interests and American national security” and seeks “peace through strength.” Its top priority is fighting “radical Islamic terror groups.” Through aggressive military operations and other initiatives, it seeks to destroy and defeat these groups, cut off their funding, expand intelligence sharing, and engage in cyberwarfare. Next, the administration aims to rebuild the American military and gain “military dominance.” And, lastly, it plans to jettison the rotten trade deals of the past and negotiate new ones that “put American workers and businesses” ahead of the “interests of insiders and the Washington elite.”

That’s it. Note the bewildering absence of any mention whatsoever of allies and adversaries. The statement says not a word about China, not a word about Russia, not a word about NATO. The statement says not a word about North Korea or nonproliferation. ...