Russian proxies in occupied eastern Ukraine shelled Ukrainian-government positions over the weekend and on Monday. The artillery barrage killed two civilians and wounded several others in Sartana, near the Sea of Azov. It’s one of the larger-scale escalations of the conflict since a winter cease-fire. Meanwhile, the Obama Administration continues to withhold a radar upgrade that would allow Ukrainian forces to protect against shelling.

Moscow and Kiev agreed under the Minsk II accord negotiated in February to cease hostilities,...