Romania, a NATO neighbor of Ukraine, lies all too close to Russia’s strikes on Danube ports.

His thatched-roof shack on the bank of the Danube River just 200 yards from Ukraine has no running water, and getting to it involves waiting for a ferry and a bumpy ride on dirt roads.

Last week, however, the farmyard home of Gheorge Puflea, 71, became a piece of attention-grabbing real estate thanks to its unwanted status as the first property in NATO territory damaged in a Russian attack aimed at Ukraine.

The drone missile assault, carried out before dawn on Aug. 2, hit a Ukrainian cargo port across the river, but it was so close that shock waves from the explosions shattered windows in Plauru, a tiny hamlet with just a dozen tumbledown homes on the Romanian side of the Danube.

The sound of the blasts and breaking glass woke Mr. Puflea from his sleep and sent him rushing outside in a panic.

“At first I thought it was a thunderstorm,” he said, recalling how he had taken shelter under a pear tree in his yard and then watched in horror as “what looked like a war movie played out right on my doorstep.”

The night sky crackled with Ukrainian antiaircraft fire, and huge fireballs rose from three Ukrainian port buildings blasted by Russian drones. A week earlier Russia had attacked Reni, another Ukrainian port across the Danube from Romania.

The Russian attacks were aimed at severing what has been a shipping lifeline provided to Ukraine by river ports, ever since the collapse last month of a deal that had allowed Ukraine to export its grain through the Black Sea despite a naval blockade by Russia. With Ukraine’s seaports too dangerous for grain-carrying vessels bound for the Middle East and Africa, its ports on the Danube have become the last shipping outlet for millions of tons of grain.

Ukraine’s main Danube ports — Izmail and Reni — have also become a potentially perilous tripwire, as they lie so close to Romania, a member of NATO, and therefore to territory covered by the alliance’s commitment to collective security. A Russian drone or missile flying a few yards off course would risk dragging the United States and its allies into a direct military confrontation with Moscow.