This resolves as YES - ONLY if US forces themselves deploy lethal weaponry during an attack on Israel to help Israel counter an attack.

This does NOT refer to American-made weaponry used by another nation.

The American use of weapons does NOT have to be lethal; by lethal weaponry, I only mean to distinguish between, say, a cyberattack, targeting information, etc.

The attack does NOT have to be by any particular nation or organization, like Iran or Hezbollah.