The trillion dollar iraq war cost harmed US economic performance massively in fact.
It stole productive capital and put it toward destruction. The debt cost then goes on perpetually in the form of interest (currently at $430 billion per year), making it even worse over time. Instead of investing into factory production, business expansion, R&D, science, healthcare, infrastructure, long-term economic growth in general, you accumulate a trillion dollars in long-term veteran care costs, and perhaps destroy hundreds of billions worth of equipment, and run up the price of oil, gasoline and commodities in general by devaluing the dollar and destabilizing the middle east - for absolutely zero real benefit.
It stole productive capital and put it toward destruction. The debt cost then goes on perpetually in the form of interest (currently at $430 billion per year), making it even worse over time. Instead of investing into factory production, business expansion, R&D, science, healthcare, infrastructure, long-term economic growth in general, you accumulate a trillion dollars in long-term veteran care costs, and perhaps destroy hundreds of billions worth of equipment, and run up the price of oil, gasoline and commodities in general by devaluing the dollar and destabilizing the middle east - for absolutely zero real benefit.