Ukraine’s once-formidable advantage in drone warfare appears to be eroding along parts of the front line. This degradation extends far beyond the immediate front—more Russian drones now prowl for targets up to 25 kilometers (roughly 16 miles) behind the contact line, and they have been hitting their targets more effectively.

I STANBUL—President Trump’s ultimatum for Russian President Vladimir Putin is showing no signs of bringing Russia and Ukraine any closer to peace. The third round of direct talks between Ukrainian and Russian officials, held Wednesday in Istanbul, yielded few results. The two sides met for less than an hour.

On the face of it, the US involvement in Ukraine bears little similarity to the 20-year Afghanistan war, not least because there are no American boots on the ground in Europe.