Honed razor keen or dull and worn out?
This Slate article argues that the War in Iraq has depleted US forces, and their equipment.
...many units are on their second and even third tours in Iraq. Many active-duty soldiers and Marines are doing near back-to-back deployments, often with less than a year at home. This relentless tempo of operations, combined with the public's doubts about the war, has hurt the military's recruiting efforts and may contribute to higher than expected numbers of officers and enlisted personnel leaving the service in the future.By contrast, this piece in the Belmont Club argues that the US Armed Forces are more effective they have ever been, thanks to the hard earned skills and knowledge you can only gather through contact with the enemy.
Meanwhile, the military is also cannibalizing its equipment stocks. Given the harsh physical environment in Iraq and the high tempo of operations there, weapons, vehicles, and other equipment have been breaking down and wearing out at a rapid rate.
...what capabilities would America need to affect Iran without actually invading it? A clue might be found in this article from SFGate: 911: FIVE YEARS LATER Military transformed -- better gear, new goals. It states the obvious, but often ignored fact, that the current US military is no longer the force it was in 2003. It is better.