By selling this hardware to the Russians, and therefore to Iran and some of Israel's other enemy states, Israel is effectively controlling the technology that the Russians and Iranians will be trying to obtain in order to counter it? This may mean that Israel will develop newer drone technology that will be immune to such possible counter measures? This is pure speculation, yet it seems we are being kept in the dark regarding certain aspects of this story.
Iran's Parliament speaker says he supports nuclear deal (AP)
from the article: Israel signs $400 million deal to sell spy drones to Russia