Despite suffering grievous losses over nearly six months of war, Russia still holds a distinct advantage over Ukraine in a head-to-head fight featuring brutal artillery battles. But Ukraine’s military has achieved some new battlefield success, waging the war on its own terms.

Supplied with a growing arsenal of long-range Western weapons and aided by local fighters known as partisans, Ukraine has been able to hit Russian forces deep behind enemy lines, disrupting critical supply lines and, increasingly, striking targets that are key to Moscow’s combat potential.

One blow to the Russians this past week was a series of explosions at an air base on the occupied Crimean Peninsula that destroyed at least eight warplanes and that a Ukrainian official said had resulted from a strike carried out by special forces troops aided by local partisan fighters.