When will the Russian (Gog) invasion of Israel take place?
I believe it will take place shortly after the rapture. If it occurred before the rapture, Christians would know the Lord is coming soon. The Bible predicts that the rapture will be a surprise event. Ezekiel's claim that Israel will be burning the weapons of war for seven years is the main reason I believe that the Gog war will take place at or near the beginning of the tribulation.
Ezekiel 39:9, KJV: "And they that dwell in the cities of Israel shall go forth, and shall set on fire and burn the weapons, both the shields and the bucklers, the bows and the arrows, and the handstaves, and the spears, and they shall burn them with fire seven years."