President Donald Trump‘s peace plan for Ukraine is music to Russian President Vladimir Putin‘s ears. Trump may be sincere in his desire to end the bloodshed, but how wars end matters a great deal. By rewarding Putin’s aggression, Trump does two things that make peace far less likely in the future.

First, he rewards aggression. Putin cares little about the human cost of the war since he himself does not have to pay the price. Russia is not a true democracy, and so the plight of ordinary Russian people does not matter. Second, Trump renders future diplomacy meaningless. Russia agreed to Ukraine’s borders in the 1991 Almaty Declaration. Three years later, Russia, the United Kingdom, and the United States committed to defend Ukraine’s sovereignty in the Budapest Memorandum in exchange for Kyiv’s forfeiture of its legacy Soviet nuclear weapons. By refusing Ukraine American support for its defense in its time of greatest need, Trump is showing that America’s word is meaningless.