As Secretary of State Mike Pompeo prepares to meet President Volodymyr Zelensky of Ukraine in Kyiv later this week, he has reportedly asked, “Do Americans care about Ukraine?”

Here’s why the answer should be yes: Ukraine is defending itself and the West against Russian attack. If Ukraine succeeds, we succeed. The relationship between the United States and Ukraine is key to our national security, and Americans should care about Ukraine.

Russia is fighting a hybrid war against Ukraine, Europe and the United States. This war has many components: armed military aggression, energy supply, cyber attacks, disinformation and election interference. On each of these battlegrounds, Ukraine is the front line.

For the last seven months, I represented the United States in Ukraine and regularly visited the front line of the military conflict. After its occupation of Crimea, Russia sent its army, security forces, undercover agents, weapons, funding and political instruction into Ukraine’s southeastern provinces of Donetsk and Luhansk, a region known as the Donbas. The 280-mile line of contact between Russian-led forces and Ukrainian forces has stabilized but has not gone quiet.