Sanctions are greatly increasing the cost of the war to Russia, and reducing their industrial capacity to wage it. Their rate of shelling as been falling steadily, and they are losing armoured vehicles at twice their replacement rate. Their spring offensive was so futile there was actually a lot of confusion about whether they actually launched it yet. They had, and it got massacred.

Easing sanctions would greatly increase the rate at which they could produce military equipment, particularly high tech guided munitions. That would equal more dead Ukrainians.