Historically, Washington has considered - but abandoned - plans to eliminate emerging nuclear programmes from the onset, be it in the former Soviet Union during the 1950s, China in the 1960s or North Korea in the 1990s.
Despite its lack of options, however, analysts agree that Washington still has some time - possibly years - to mull over difficult options such as a strike.
The London-based International Institute for Strategic Studies estimates Iran will still need between three and five years to acquire a bomb.
Washington runs out of options as Teheran pursues its own agenda
By William Choong, for the Straits Times
CANBERRA - THE diplomatic dance over Iran's nuclear dispute continues - with Teheran offering more talks but no sign of stopping uranium enrichment, a process that will eventually make it a nuclear power.
Essentially, Iran's dogged refusal to stop uranium enrichment activities, pending further talks, has put it on a collision course with the US.
On Monday, the country's Supreme Leader Ayatollah Ali Khamenei ruled out any concessions.
'The Islamic Republic of Iran has made up its mind, based on the experience of the past 27 years, to forcefully pursue its nuclear programme and other issues it is faced with, and will rely on God,' he said.
In the short term, the United States has practically run out of options on Iran.
Even if Russia and China could be railroaded into implementing sanctions, the measures would do little to curb Iran's nuclear ambitions.
Oil-rich Iran is benefiting from an oil price boom, while a US sanctions regime imposed since 1979 has not had significant impact.
For now, Washington will have to depend on the cost-effective strategy of deterrence: using the threat of massive retaliation if Teheran ever decides to employ nuclear weapons in a future conflict.
'We've lived with Iran as a terror threat for a generation. Iran has a return address, and states with a return address can be retaliated against,' Dr Stephen Biddle, the senior fellow for defence policy at the Council on Foreign Relations, told the New York Times.
In the long run, analysts in Washington are hoping for either an implosion or change in the Iranian regime.
Barring this, a preventive military strike will have to figure by 2010 - roughly the time when Iran is expected to become nuclear-capable.
Bush administration officials, however, refuse to stomach the concept of a nuclear-armed Iran.
Mr Nicholas Burns, the under-secretary for political affairs at the State Department, argues that it is 'entirely unconvincing' to live with a 'radical Iran' that has threatened to wipe Israel off the map.
In short, he subscribes to US President George W. Bush's take on Iran - 'all options are on the table' - which is diplomatic-speak for a preventive strike at Iran's nuclear facilities.
Mr Edward Luttwak, senior adviser at the Washington-based Centre for Strategic and International Studies, accepts that a preventive strike is an option down the road.
Given that some sympathetic engineers and scientists within Iran have been feeding the West a steady flow of 'detailed and timely information' about Iran's nuclear facilities, it is possible to overcome Teheran's attempts at dispersing such facilities to avoid a strike.
'How could deterrence work against those who believe in the return of the 12th Imam and the end of life on earth, and who additionally believe that this redeemer may be forced to reveal himself by provoking a nuclear catastrophe?' he writes in Commentary, a neo-conservative magazine.
Historically, Washington has considered - but abandoned - plans to eliminate emerging nuclear programmes from the onset, be it in the former Soviet Union during the 1950s, China in the 1960s or North Korea in the 1990s.
Despite its lack of options, however, analysts agree that Washington still has some time - possibly years - to mull over difficult options such as a strike.
The London-based International Institute for Strategic Studies estimates Iran will still need between three and five years to acquire a bomb.
This, however, would mean that Teheran would have to enrich uranium - a key material used in nuclear weapons - at a far higher rate that what it is estimated to be doing now.
What worries Washington, however, is the gnawing reality that Teheran is slowly, but surely, emerging as a new power in the Middle East - oil-rich, potentially nuclear capable, and a sponsor of proxy terrorist groups such as Hizbollah.
'The Iranians, correctly or otherwise, perceive that their moment in history has arrived,' says Strategic Forecasting, a US-based commercial intelligence firm.
'And for the US, like its Western allies, there are few meaningful options left to block it,' it concludes.
