Every scholar of international affairs learns about alliances. Understanding why states choose to collaborate on matters of security is a simple prerequisite for undergraduates just beginning to dip their toes into the field. The topic is particularly relevant to U.S. foreign policy: In the post-World War II era, the United States has constructed an international order of overlapping partnerships that have produced a safer and more prosperous world.

Donald Trump is no scholar of international affairs.

Over the weekend, the reality TV star turned GOP nominee for leader of the free world tweeted out one of his classic burns. The target? Apparently, the world at large: “The U.S. has 69 treaties with other countries where we would have to defend them and their borders. How nice, but what do we get? NOT ENOUGH”

As usual, we must first note that Trump is not being fundamentally factual. Micah Zenko, a senior fellow at the Council on Foreign Relations, pointed out on Twitter that Trump should be referring to seven treaties rather than 69 — the latter number presumably comes from the total number of countries the seven treaties cover, although in total, the treaties only really apply to 54 nations, charitably including a few that have bowed out of those treaties in the past.

The bigger problem with Trump’s assertion, however, is that the seven treaties he is citing are not one-sided arrangements but rather mutual defense pacts, meaning that all signatories pledge to come to the aid of any one that is attacked. Trump suggests — both in his tweet, and often throughout his campaign — that these are standing contracts requiring the United States to defend others with no reciprocity, but this simply isn’t true.

The ‘mutual’ part of these mutual defense pacts isn’t an abstraction as it pertains to the United States, either. NATO provides a concrete example grounded not in arcane notions of great power warfare, but the world’s more recent struggles against terrorism. Less than 24 hours after the attacks on 9/11, NATO invoked Article V — the part of its charter that rallies every member to the defense of one attacked — which ultimately led to the alliance’s joint work in fighting the Afghan Taliban.

So Trump lacks an understanding of how many treaties the U.S. is a party to, how many countries those treaties include, and the fact that those countries will defend the United States when we ask them to do so. Yet it is clear from his continual calls for a tribute-based foreign policy that he ignores the second- and third-order benefits of alliances, too.

First, alliances open the door to a wider range of collaboration. In an age in which combating extremism is one of the top international security priorities, intelligence sharing is an absolute must; the connections between disparate and (necessarily) secretive national security agencies are made stronger by formal alliance structures. Trump may claim that he “alone can solve” the problem of terrorism, but tracking the movements of dangerous individuals the world over is a hard job to do all by one’s lonesome.

Alliances also help to ensure that conflicts are legitimate. Allies can be a key driver in considering the case for war rather than rushing to quick action — contrast the strong case built for the first Gulf War to the hurried, unpersuasive rationale for the invasion of Iraq. Trump’s United States would be a wonton force of nature, “bombing the shit outta” anywhere he pleases and purposefully murdering noncombatants. That’s a far cry from the measured approach that the Greatest Generation tried to establish in the wake of the Second World War.

Finally, alliances promote active interoperability between militaries. Conducting joint exercises sends a clear signal to rival countries — military demonstrations in the South China Sea, for example, check China’s unilateral attempts to redraw boundaries there. It is also wise to ensure that partner militaries purchase reliable American-made military hardware — and the replacement parts, upgrades, and training programs that go with them — that keep cooperation close for years. Trump alleges he would make our military great and powerful, but the rhetoric he consistently advances would only reduce the number of partners it can work with.

To be sure, its wealth of alliances does not make U.S. foreign policy perfect. We have always had relationships — sometimes mutual defense pacts, sometimes other arrangements — with less than savory countries in the name of various security-related goals. Pressing our international friends and acquaintances towards the values we want to see reflected in the world is the hard work of every new administration.

Yet Trump doesn’t make his arguments against alliances for the sake of human rights. He sees the notion of collective defense as a protection racket for which the United States is being insufficiently paid. In undoing these alliances, Trump would push the United States and the world back to a diplomatic era before World War II, when great powers did go to war with one another — to frequent and devastating results.

Perhaps someday Donald Trump might stop knocking our allies long enough to consider the implications of his lies about treaties. But of all the inconsistencies and policy reversals we’ve seen from the presumptive Republican nominee so far, this one unfortunately seems the least likely.

Graham F. West manages The Whistlestop (@thewhistle_stop), a platform for holding candidates and elected officials accountable on issues of national security and foreign policy throughout the 2016 cycle. Views expressed are his own.

Photo: Republican U.S. presidential candidate Donald Trump addresses the Rolling Thunder motorcycle rally to highlight POW-MIA issues on Memorial Day weekend in Washington, U.S. May 29, 2016.  REUTERS/Jonathan Ernst