Even with the finest speechwriters, President George W Bush never quite hits the rhetorical heights of some of his more spellbinding predecessors. But his inaugural speech last week, the first since America was changed for ever by September 11, pressed many of the right buttons. As a statement of his country’s modern-day mission, the pursuit of liberty and freedom around the globe, it could hardly have been more eloquent.

Lofty visions, however, carry practical obligations. The first international obligation is to complete the job in Iraq. With a week to go before the elections, it is clear that the orgy of violence, much of it directed at the Shi’ite majority, will continue. That in turn means the elections will be only a partial reflection of the will of the Iraqis. The Sunni minority has been urged by its leaders to boycott the polls and many others will stay away for fear of the bullet and the bomb.

So while next Sunday will mark a watershed for Iraq, it will not make the country any easier to govern, initially at least. Abu Musab al-Zarqawi, the most repugnant of the militant leaders, has warned of a conflict against America and its allies in Iraq that will last for years. Mr Bush has to be prepared for this, even if it means a significant American presence, including a steady toll in casualties, beyond his presidency.

If Iraq is a challenge, Iran is even more so. Tehran is clearly developing nuclear weapons that pose a threat to its neighbours and possibly beyond. It is committed to the destruction of Israel and is a state sponsor of terrorism, most notably Hezbollah. Iran ticks more boxes in the war on terror than Iraq ever did. Dick Cheney, the vice-president, said Iran was “right at the top of the list” of potential trouble spots. Condoleezza Rice, secretary of state, said Iran was one of six “outposts of tyranny”, along with North Korea, Cuba, Zimbabwe, Belarus and Burma. If Iraq has dominated Mr Bush’s first term, Iran seems certain to claim the spotlight in the second.

But how? While using tough language, the president and his team are careful to express their public support for the initiative being pursued by Britain, France and Germany in which Tehran is being pressed diplomatically to surrender her nuclear ambitions. Privately, however, senior figures in the administration view this exercise with the same scepticism as they did the United Nations’ process ahead of the invasion of Iraq.

Dealing with Iran is essential but diplomacy, followed by tougher sanctions if necessary, should be the preferred route. Sanctions, some of which are already in place, were once belittled but showed themselves to be effective, albeit slowly, in helping to bring about change in South Africa and Libya. Military action would be difficult, not least for America’s allies. Our poll today shows that voters would oppose British participation in action against Iran by four to one. It is the last thing Tony Blair wants. Iran has to be stopped. The question is whether it can be done without using force.