Opec officials say there is enough spare capacity to satisfy demand and keep prices stable even if a war with Iraq were to erupt.
However, some energy analysts argue that simultaneous stoppages - if the war were to erupt during a general strike that has paralysed crude exports from Venezuela - would strain the Organisation of Petroleum Exporting Countries to cover the shortfall.
Opec officials declined to discuss exactly how much spare production capacity its members can bring to bear in an emergency.
Experts believe it is unlikely exports from both Venezuela and Iraq would cease at the same time. Venezuela's strike would probably end by early January and a possible war with Iraq is still widely believed to be several weeks away.
Saudi Arabia, which accounts for about 3 million barrels a day of Opec's surplus capacity, could boost its production by this amount within one month if necessary.
In case Opec could not meet a shortfall, the International Energy Agency has discussed coordinating the release of oil from its members' strategic reserves.
The US Strategic Petroleum Reserve alone contains 600 million barrels and can supply 4.3 million barrels a day for up to 90 days. Japan and Germany, the world's second and third-biggest economies after the United States, could each supply a bit more than half of that amount for as much as 60 days.
Together, these three countries could provide an additional 8 million barrels a day for 60 days.