Blix was in Rome to take part in an international gathering of experts on nuclear proliferation that was held, coincidentally, during President Bush's three-day stop in the city. "The military threat may well be counterproductive," Blix said at a news conference. "It is more likely to strengthen the ranks in Iran."
The veteran Swedish diplomat, who tried to avert the 2003 US-led invasion of Iraq because no weapons of mass destruction had been found by UN inspectors, said stronger economic sanctions are more likely to force Tehran to compromise on its nuclear program.
"The rewards are more important, the carrots rather than the sticks," he said. He said the United States and Europe should offer incentives – including support for Iran joining the World Trade Organization, improved economic relations and guarantees against outside attacks and attempts to topple the Iranian regime.
Before traveling from Berlin to Rome on Wednesday, Bush reiterated his previous statements on the issue, saying he favors a peaceful resolution to the standoff with Iran but has not ruled out force. Earlier, during the EU Summit in Slovenia, Bush warned that Iran, if armed with a nuclear weapon, would be "incredibly dangerous for world peace.
"So we've got to continue to work together to make it clear, abundantly clear, to them, that it's their choice to make: They can either face isolation or they can have better relations with all of us if they verifiably suspend their enrichment program," he said.
The Israeli stance
Iran maintains its nuclear program is aimed generating electricity. But the United States and some of its allies fear Iran is secretly trying to develop atomic weapons.
The UN Security Council has imposed three sets of limited sanctions against Iran for refusing to halt uranium enrichment, a technology that can produce both nuclear fuel and the material needed for nuclear warheads.
Uzi Arad, director of Israel's Institute for Policy and Strategy, disagreed with Blix. As long as it is made clear that it is a last resort, the threat of military action could push Iran to comply with the international community's demands, he said.
"The fact that there is such an option is very healthy in concentrating Iranian minds," Arad told reporters. "The existence of the military option increases the chances of a nonmilitary solution."