Wouldn't cutting off all your neighbor's main revenue source and attacking their civilians shipping be considered an act of war?

I'm just trying to understand why this is even a "good option?" If you're losing a war against one neighbor, why would you try to indirectly attack them by attacking all your other neighbors?

Also, hasn't Iran been fighting the Taliban and bombed by Pakistan lately for supporting terrorists against them too. What's the deal with everyone disliking them?