Michael Axworthy makes a good case that seeking regime change in Iran is both unnecessary and would be disastrous in the unlikely event that it succeeded:
A country that is essentially defensive and pragmatic in its foreign policy, and resilient internally, is not a good candidate for regime change. In its effective opposition to the Islamic State and similar groups, and its actions favoring regional stability, Iran deserves at least some praise, rather than blame. The sensible policy would be to accept the existence of the Islamic Republic, to hope for its evolution in a more liberal direction perhaps, but to let Iranians decide that for themselves.
I agree with all of this, and I have said something similar in the past. All that I would add to this is that a policy of regime change in Iran isn’t just a disaster waiting to happen, but it is also profoundly wrong in principle. Even if the U.S. has the means to overthrow Iran’s government, it would be wrong to try. It is not for our government to decide whether a foreign regime should be replaced. The only ones with both the right and responsibility to make that decision are the people living in the country that the regime controls. We should not presume to force political change there or anywhere else, but should instead respect the sovereignty and independence of other nations while seeking to have peaceful relations with as many states as possible.
To that end, it is long past time that the U.S. reestablish normal relations with Iran. I have no illusions that this will happen under the current administration, but it ought to be part of the policy debate here in the U.S. The U.S. has normalized relations with many much worse governments and with many other former and current adversaries, and it makes no sense that we have not done so with Iran almost forty years since the revolution. Doing this would help reduce tensions between our countries, and it would create a channel for resolving outstanding disputes and it would make it easier to cope with unexpected incidents and crises. It would be squarely in our interest to do so because it would give our government the means to deal directly with Tehran on a regular basis. That would reduce the danger of misunderstandings that could lead to a clash somewhere down the road. Instead of chasing after fantasies of toppling a government that has been in place for almost four decades, the U.S. should be exploring how to improve relations with them for the benefit of both parties and the wider region.