Wonder where and Iranian got the word "quadmire?"
From a typo? :)
Seriously, I see your point. They seem to have a very familiar play-book...
China, Russia, India, and Europe don't want us to get into the war with Iran.
Iran has 5% of the world's oil. If we do respond to aggressive ravings from Ahmadinejad, there will probably be a Global shortfall in the amount of oil available. This will probably last about a decade. A decade of a shortfall in oil will lead to a Global Depression. The Straights of Hormuz will probably close, so there won't be much oil coming out of the Persian Gulf.
The United States might be able to survive. A decade is a long time.
Much of Iran is mountainous. Iran does have more military forces than Iraq did. Iraq was sanctioned for many years. Iran probably has some aircraft and missles. Iran has operational control of Hizbollah, and maybe strong influence over the majority Shia' Muslims in Iraq. Tehran is in a valley, I believe. The CIA world fact book probably has more information on Iran. The Iranian intelligence apparatus is probably much more formidable. (Though honestly, with some of the pronouncements coming from Ahmadinejad, sometimes I question that.)
If Ahmadinejad does draw us into the fight, China might decide that now is the time to Take back possession of Taiwan, and while it is being militant, it might also go for Japan. Russia could decide to take parts of Europe.
Russia has resources (oil), both China and the US need oil. If we are drawn into Iran, we probably won't continue with the globalization program of manufacturing goods in China and shipping them across the world. That will have other effects.