Iran has bought lots of weapons from Russia in the past years and from other sources secretly. And managed to produce some on its own. But the power doesn't lie only in the weaponry but also in the large young population who are serving military. Don't forget Iran had world's 5th strongest army and weaponry before the revolution.
For some information you can go to http://iranmilitaryguide.itgo.com/
Here's an interesting article.
What if the United States drops assorted non-nuclear weapons on Iran before the bourse opens? The potential targets are many; the underground facilities will be hard to destroy. But what if all of them are taken out?
Iran instantly wins the legitimacy sweepstakes. Dr. Ahmadinejad becomes the first universally respected Shi'ite political leader in the Sunni- and Wahhabi-dominated Middle East. All across the Middle East, restive Muslims in the streets will start murmuring: "Where is our leader? Why doesn't he stand up to the United States?" The answer is obvious: because he has long been bought off by the United States. Because, in the immortal words of Lyndon Johnson, the United States has his pecker in its pocket.
There will soon be a lot of newly exposed members at risk. An unprovoked American attack on Iran will instantly and permanently de-legitimize every American client state in the Middle East. If the United States bombs Iran, the Bush Administration might as well send that "Mission Accomplished" banner to Al Qaeda headquarters.
President Bush can issue warnings. The Administration can talk tough. But what is the point? The President of Iran can call the President of the United States's bluff, if it is a bluff. He is doing this, day by day. He is not going to cooperate with the United Nations. There is no need to. If it is not a bluff, and the bombs fall, the United States' client regimes in the Middle East are as good as gone. We will then be driven out of Iraq. This message will be fully understood by every Muslim in the street. The Great Satan can be whipped. No better reason exists to start looking for a local client to whip.
Iran cannot be occupied by U.S. troops. As retired four-star general and NBC commentator Barry McCaffrey said in mid-2005, the wheels are already close to coming off the Army's machine in Iraq. So, the enforcement of any anti-nuclear technology development program is a bluff.
Iran's program can be delayed a few years by bombing, but only at the price of solidifying Dr. Ahmadinejad's rule in Iran and making him a regional symbol of Islamic defiance. In this non-elected office, he will replace Osama bin Laden. The difference is, Ahmadinejad is a legitimately elected President of a nation with a lot of oil.
This is about oil, political power, currencies, and above all, legitimacy. It is about the ability of the United States to change regimes its way and then preserve these new regimes from replacement by domestic enemies. The United States and its client state regimes will be replaced in the Middle East. It is only a matter of time. If the United States bombs Iran, the timetable will speed up.