Newly minted Defense Secretary Pete Hegseth was being honest with Ukraine when he said the country will not return to its pre-2014 borders anytime soon. The same goes for his statements that Kyiv should not expect NATO membership as part of an agreement to end the war with Russia, and that the United States cannot be expected to shoulder the burden of supporting Ukraine going forward.

These were harsh realities for Ukrainians to hear, perhaps — but they are realities nonetheless. Hegseth’s candor is to be welcomed. But while the secretary of defense has gone a long way toward articulating a more realistic policy on Ukraine, it is important that one false hope is not exchanged for another.

In particular, President Donald Trump’s team should clarify what Hegseth meant when he said that “robust security guarantees” will be needed “to ensure that the war will not begin again.” To state the obvious: security is a hard thing to guarantee. It almost always requires the threat or use of force. But who will use force to uphold Ukraine’s postwar borders?

Hegseth seems to have accepted the inevitability of “peacekeepers” being tasked with implementing a future peace agreement. If true, however, this would be a concerning development. To be sure, Hegseth appeared to rule out U.S. participation in any peacekeeping force and rejected a role for NATO’s alliance structures. Instead, he referenced “capable European and non-European troops” as candidates for guaranteeing Ukraine’s postwar borders.

But there is a real risk of “peacekeeping” being used as an appealing shorthand that lures policymakers into believing that security can be provided on the cheap or without loss of life. Nothing could be further from the truth. As Irish peacekeepers in Lebanon and Uruguayans in the Democratic Republic of Congo can attest, peacekeeping missions are difficult to establish and often deadly to maintain.

There are basically two types of peacekeeping forces. First, there are peacekeepers who exist with the consent of the warring parties. These forces are deployed when both sides to a military conflict agree on a peace agreement and request that a neutral third party is given the job of upholding some of the terms.

Clearly, Russia will never agree to Europeans assuming such a role. This is for the simple reason that most European countries are not neutral, and so Moscow will never trust them to serve as impartial arbiters. It is technically possible that a neutral non-European government could provide military personnel for such a mission, but it is hard to imagine Russia being deterred as a result.

Second, there are peacekeepers who are deployed without the consent of one or both belligerents — usually at the direction of an international organization such as the United Nations. These might properly be called peace “enforcers” (not “keepers”) because their job is to impose a settlement upon combatants who do not recognize a peacekeeping mandate.

This is a nonstarter in the context of Ukraine. To do their jobs, enforcers must be willing to use hard power to gain compliance. But there is no government in the world that wants to select into a shooting war with nuclear-armed Russia — a lesson that Ukraine has learned the hard way over the past three years.

For these reasons, it is probably wishful thinking to imagine a traditional peacekeeping force for Ukraine. So, why does the idea of peacekeeping continue to be raised?

The answer is that when President Volodymyr Zelenskyy and other European leaders talk about peacekeepers, they mean something quite different from the textbook definitions. Their undisguised hope is that a NATO army will be stationed on Ukrainian soil for the purpose of deterring Russia from invading again. This is why Zelenskyy has always insisted that U.S. participation would be essential — because he wants powerful allied forces to be based along his frontier with Russia, not neutral peacekeepers.

To be clear, this would not be peacekeeping. Those who use the vocabulary of “peacekeeping” to advance the idea are playing fast and loose with the word, likely on purpose. What they actually want is Ukraine’s de facto inclusion in NATO. This is something that the Trump administration should oppose because it would be wholly at odds with U.S. policy and interests, risking a hot war with Russia.

Peacekeepers are not a solution to Ukrainian insecurity, now or for the foreseeable future. The only real way to guarantee Ukraine’s postwar borders will be to arm Ukraine such that it can deter renewed Russian aggression by credibly threatening to defend itself. This is an outcome well within grasp, and the Trump administration should work with European partners to make it happen. In the final analysis, talk of peacekeeping is an unhelpful distraction from this more achievable goal of armed neutrality for Ukraine.

Peter Harris is an associate professor of political science at Colorado State University and non-resident fellow with Defense Priorities.