Defense Secretary Chuck Hagel’s visit last weekend to Georgia was a reassuring gesture to a former Soviet republic that has assisted the United States in recent conflicts and is increasingly worried about Russia’s expansionist streak.

Georgia’s long quest to join NATO is understandable. Russia occupied two territories in Georgia that make up roughly 20 percent of the country’s land when the two nations fought a war in 2008. After Russia annexed Crimea in Ukraine in March, Georgian leaders feared their belligerent neighbor would try to seize land along its border, where many ethnic Russians live.

The United States and NATO allies face a tough balancing act as they seek to bolster militarily weak former Soviet republics that have been partners — though not members — of the alliance. Putting Georgia and Ukraine on the fast track to NATO membership could provoke a severe response from Russia at a time when Western leaders are trying to cool tensions in the region. It also could drag the alliance into armed conflicts it cannot afford given the daunting challenges in Iraq, Syria and elsewhere. But the Obama administration is sensibly taking measured steps to reassure Georgia, Ukraine and Moldova.

Mr. Hagel’s visit to Tbilisi, the first by a defense secretary in more than a decade, struck the right encouraging tone. “Because Georgia is such a committed and dependable partner of the United States,” he said, “we want to and will continue to help Georgia fulfill its Euro-Atlantic aspirations, including membership in NATO.”