Throughout my time in Kyiv, hope for a future free of Russian domination was everywhere. But it was not to be. Political infighting, corruption and a lack of progress on integration with Europe paved the way for Mr. Yanukovych’s narrow win in the 2010 presidential election. Three years later, he ditched a treaty bringing Ukraine and Europe closer together, choosing stronger ties with Russia instead.

Another massive protest movement erupted, but this time people were massacred in Maidan by snipers. Mr. Yanukovych fled to his owners in Russia, which swiftly invaded Crimea. Since then the Russian shadow has loomed over Ukraine. With a full-scale war now under way, the country is at risk of being swallowed whole.

The Ukrainian people will fight—especially, but not only, in the country’s west and center, where love of freedom runs deepest. In 2004 that meant making orange flags and setting up orange tent cities. This year, and likely for many years to come, it means making Molotov cocktails and setting up a resistance. Ukraine will never surrender.