AQ never had a military. ISIS does, sort of, but the US never really attacked them (too busy arming them).
As I indicated previously, guerilla wars may be unwinnable. My point was about conventional wars.
Unless you prepared to exterminated Iranians you will deal with endless waves of their conventional troops. If much weaker opponent then them strained our military to the breaking point what do you think foolishness with them will do?
Here are some news we seen lately.
Yemen Iran supplied cruise missiles keep causing damage upon Saudis and US.
We had problem with making enough bombs years back when we were in Iraq and Afghanistan.
We have problems treating all out vets after Iraq and Afghanistan.
We still lose troops to dudes with AK47s.
We bombed and air field and thin layer of concrete almost neutralized our missiles.
Iran has military bases in mountains. With steel doors and etc. Not some soviet era cave base in Afghanistan.
20 trillion in debt and no end in sight of increased spending.
How long do you think we can maintain a campaign under these facts? How effective you think we will be considering 10 years later Afghanistan and Iraq are a mess?
There is only two ways to win this war, and right now anyone in the west who would give this order would be lynched. Nukes or civilian targets.