By withstanding and pushing back Vladimir Putin’s unprovoked invasion, Ukrainians determined that their future as a sovereign state is theirs alone to decide. In doing so, Ukraine galvanized the West to mount decisive sanctions and military aid to Ukraine that have crippled Russia’s ability to wage wars of conquest, thereby enforcing international laws on self-determination. Ukraine’s resistance, the West’s unity, and Russia’s naked aggression have sharply elevated public support for the post-World War II order governed by international rules regarding self-determination, democracy, and human rights, and institutions like the EU, which were formed to place these principles in action. It has also proved the indispensability of NATO to Eastern European member states who fear potential invasions by Russia and Western political and economic unity on deterring Russian aggression. These groundbreaking precedents may also protect the rights of vulnerable countries far beyond Europe’s borders.