Are you serious? This is utterly juvenile take on events.
1. Pakistan has nothing to do with Iran and its proxy wars in the ME.
2. Declaring WAR on USA is absolutely stupid. Not long ago, Iranians were boasting about shooting down an American UAV and attacking a Saudi oil refinery; some were boasting about US not having in it to counter Iranian moves. Well, Trump administration is calling the shots now.
3. WAR does not break US economy, rather help it. Military Industrial Complex is an important component of American economy.
4. Assassination of top Iranian general wasn't an impulsive act. This show that US is absolutely prepared and willing to safeguard its interests across the board. In fact, Mike Pompeo have conveyed as much to Pakistani COAS as well.
Pakistan must stay away from this war no matter what. WE have too much on our plate already. Time to seal Iranian border.