by Stephen Collinson Sun Oct 14, 11:57 AM ET
WASHINGTON (AFP) - The specter of a hypothetical US military strike on Iran is emerging as a dominant foreign policy theme in a 2008 White House race already haunted by the war in Iraq.
The campaign trail is hardly the place for diplomatic nuance and candidates are facing questions they might rather avoid, about how they might deal with the Islamic Republic should nuclear diplomacy fail.
The issue has opened a new line of attack for Democratic front-runner Hillary Clinton's rivals Barack Obama and John Edwards, who hope to cut her opinion poll lead by convincing voters she lacks judgment.
Republicans meanwhile spar over whether Congress would have to authorize any use of force against Iranian nuclear facilities, and one candidate, Senator John McCain, warns ominously such a choice may be closer than anyone thinks.