By Fareed Zakaria, CNN

Regular GPS watchers and readers will know that I was in Tehran last week to interview President Mahmoud Ahmadinejad. You can watch excerpts of the interview here. But being in Iran made me think about our policy towards that country, which strikes me as stuck in a time warp.

You will remember that early in the 2008 presidential campaign, Barack Obama signaled that he was going to have a different foreign policy than George Bush - and he chose as his example, Iran. He argued that simply pressuring the country was not a policy and Obama offered to talk to Iran's leaders. Well, two years into his presidency, Obama's Iran policy looks a lot like George W. Bush's - pressure and more pressure.

The punitive tactics have paid off in some measure. Iran faces economic problems. But they are also having a perverse impact on the country, as I witnessed last week. The sanctions are stifling growth, though not as much as one might imagine. So the basic effect has been to weaken civil society and strengthen the state - the opposite of what we should be trying to do in that country. By some estimates, Iran's Revolutionary Guard - the hard-line element of the armed forces, supported by the supreme leader – now controls 40% of the economy.

Is that the goal of our policy?

In fact, what is our goal? Is it to overthrow the Iranian regime? Is it to make it bleed until it gives up its nuclear program? A wholesale revolution continues to strike me as a distant prospect. The regime still has some domestic support, and it uses a mix of religious authority, patronage and force quite effectively.

And we keep forgetting the inconvenient fact that, even if the regime changed, the nuclear energy program - which is popular as an expression of Iranian nationalism and power - will continue. Even the leaders of the Green movement strongly support that program.

Obama should return to his original approach and test the Iranians to see if there is any room for dialogue and agreement. Engaging with Iran, putting its nuclear program under some kind of supervision and finding areas of common interest (such as Afghanistan) would all be important goals.

It might not work - the Iranian regime is divided and often paralyzed itself - but it's worth trying. Strategic engagement with an adversary can go hand in hand with a policy that encourages change in that country. That's how Washington dealt with the Soviet Union and China in the 1970s and 80s.

Iran is a country of 80 million people, educated and dynamic. It sits astride a crucial part of the world. It cannot be sanctioned and pressed down forever. It is the last great civilization to sit outside the global order. We need a strategy that combines pressure with a path to bring Iran in from the cold.