Why will the northern confederation launch a surprise attack at that particular time?
The northern confederation attacks then because Israel is dwelling safely and securely in unwalled villages, with neither bars nor gates. Seeing this defenseless condition, they think an evil thought and say they will go up to the land of unwalled villages.
Les explains that Israel is looking for physical safety from their enemies, and the Antichrist will promise exactly that, which they will swallow hook, line, and sinker. Then the northern confederation—more than just the Russians, a consortium of nations—will suddenly realize that here sits a people with unwalled villages, dwelling safely. God speaks through the prophet, saying they will ascend like a storm, like a cloud to cover the land, a massive invasion army. At that same time, things come into their mind, and they think an evil thought, saying, 'I will go up to the land of unwalled villages.' Israel is now sitting relatively safe and secure, so it is the time for a surprise attack, because all are dwelling without walls, bars, or gates.