Iranian communities around the world are wondering whether their country might become the next in line for a US-led campaign aimed at "regime change".
The US has long accused Iran of developing nuclear weapons, while the Iranian authorities say they are only using the technology for civilian nuclear energy.
Iranians abroad, regardless of their degree of political engagement for or against the regime in Tehran, share a common view: military intervention, even in the form of targeted strikes, would have catastrophic consequences and possibly end up strengthening clerical dominance of Iran's political system.
The BBC News website spoke to four exiled or expatriate Iranians about what they thought of the possibility of a military attack.
Mahmood Amiry Moghadam, 33, has been living in Norway since the mid-1980s. He is a medical doctor working at the University of Oslo.
The possibility of an attack has been there for some years now, ever since the US said Iran belonged to the "Axis of Evil".
An attack on Iran would be unacceptable for most Iranians, even though most of us still look at the Iranian government as our main problem.
We want a change of regime, but we want it to happen at the hands of the Iranian people and not through a military attack.
In fact a military intervention would play into the hands of the mullahs, because it would end up fuelling anti-Western feeling among a population.
As to the consequences - I would rather not think about it. It would be a much, much bigger and bloodier war than the Iraq war, because Iran would be much harder to conquer due to its landscape and size.
I also think that it's a little paradoxical that Americans are using such tough language with the Iranian government while at the same time they have been tying the hands of the main Iranian opposition groups.
So I don't think it is necessary for Western countries to interfere, but they should stop helping the regime economically, and stop restraining the opposition.
Niloufar, 36, has been living in the UK since 2003.
I have only been in this country for a couple of years and I don't know many Iranians here, but the ones I am in touch with are completely against any military attack on Iran by the Americans - even though they are unhappy with the current regime.
It must be said that the people I know are not members of organisations actively opposing the current regime in Iran.
Those people's views might well be different, but I'm not in touch with them.
There are some Iranians who have been living abroad for 30 years or more, they have never been back to Iran and don't really know what is going on there.
All they hear is that the mullahs are ruling and that the country is torn apart, but because they haven't been there for so long they have lost that special connection to Iran and don't really know people there feel about this issue.
So they might well think an attack would bring freedom to the country and allow them to move back. But I think this is a very optimistic view.
I think that the situation would be similar to what we saw in Iraq: a war would result in many innocent Iranians being killed and the situation will only worsen.
Even though you do occasionally hear from Iranians that they wish there would be a war to free the country from the mullahs, I am sure that 90% of the population is actually against it.
The last thing they want is more conflict, even though they are not happy with the situation there.
Ramin Mahjouri, 41, live in Vancouver, Canada, and is editor of Paivand, a newspaper serving the Persian community in Canada. He also hosts a radio phone-in show.
Among the Iranian community here there is a sense of disbelief. People don't really see it happening.
A few years ago, some people would have been in favour of some military action. Now all they want is to get rid of this oppressive regime, but from inside.
Western countries could help by means of sanctions or by supporting Iranian factions which oppose the regime.
People who phone in express their concerns and their reactions vary from total denial to complete despair.
From personal experience I must also say that the Iranian community abroad is extremely apolitical and hard to mobilise.
There is no doubt though that if an attack should take place, people would definitely do something about it.
Iran is a very diverse country and a brief look at its history will prove that defining and measuring consequences is a difficult task.
One could imagine the normal consequences though: demonstrations and protests both inside and abroad; urban war against the invaders or attackers, needless loss of human lives both military and civilian...
Even though people want the political situation to change, they want this to happen from inside out - it's a matter of national pride, you don't want an external hand to remove the current rule.
M, a 34-year-old teacher, moved to Washington DC from Iran two years ago.
Here in the US, the Iranian community is split into two sides: Republican Iranians would be very happy if there was an attack, while Democratic Iranians are totally against it.
Here in Washington DC they are mainly Democrats, but from what I have heard about Iranians in Conservative states, Florida for example, they have voted for George Bush because they think he will attack Iran eventually, and they want it to happen.
They want a regime change and don't care about the consequences. I think they are being selfish.
But from what I can hear, most people are against it.
They have got relatives and acquaintances there, and are worried it might turn into a second Iraq. A military action would create lots of problems for people in Iran, it would damage the infrastructure and make them live without electricity, without gas...
Until a few weeks ago, people in our community didn't seem to be taking this threat very seriously. The reason is, they believe the US has not enough troops left because so many soldiers have been deployed to Iraq.
But day after day, I can see that people, including my husband, start growing concerned.
America is so strong that I think that even though this would be a much more complex conflict than Iraq, they would eventually manage to change the regime. But God knows how many people would suffer.
With regard to the current regime, I am not a political person and I have never seen the country in another period of time because I was a child when the regime changed.
Of course I would like to see democracy and freedom in the country, but I don't want millions of people to suffer to reach that objective. I hope there will be some diplomatic solution to the problem - I definitely don't want a war.