More than four years ago, US President George W. Bush branded them charter members of the “axis of evil”.

Now the three countries he targeted, Iraq, Iran and North Korea, are haunting the final years of his presidency, topping the list of unresolved foreign policy problems he likely will leave to his successor.

North Korea’s missile tests this week in defiance of US and international warnings underlined the growing sense that Bush’s legacy in world affairs, something aides say he thinks about more and more these days, is increasingly at risk.

“He identified these states as threats but seems unable to move toward acceptable solutions,” Georgetown University political scientist Stephen Wayne said. “Future presidents will have to deal with the repercussions of his rhetoric.”

Overhanging Bush’s foreign policy challenges are his low approval ratings, now languishing in the mid-30s, among the worst poll numbers of any president facing midterm congressional elections.

The November ballot, in which Bush’s Republicans fear they could lose control of the US Congress, adds to pressure to show progress on national security, the centrepiece of his administration’s policy since the September 11 attacks.

Bush may be able to turn the tables on the Democrats if he can convince voters — as he did with some success in the 2004 presidential election — that only the Republicans can be trusted to protect America against such global dangers.

Foremost among Bush’s challenges is Iraq, where US-led forces remain bogged down fighting a bloody insurgency almost three and a half years after toppling Saddam Hussein. More than 2,500 US military personnel have died there.

Bush received a boost last month from the killing of al-Qaeda’s leader in Iraq, Abu Musab al-Zarqawi, and the creation of an Iraqi unity government, but any benefit in terms of domestic popularity appears to have been short-lived .

A new Time magazine poll showed two out of three Americans disapprove of Bush’s handling of the situation in Iraq.

Analysts say the massive, open-ended US commitment in Iraq — nearly 130,000 troops on the ground and $320 billion spent — has limited the administration’s flexibility in dealing with other world crises.

“Here you have a shoot-from-the-hip president who is out of ammunition,” Wayne said.

Engaged so deeply in Iraq, Bush has had little choice but to play down the potential use of force against Iran and North Korea, focusing instead on diplomacy.

He also has backed away from the go-it-alone approach used in Iraq and tried to forge an international consensus against Tehran and Pyongyang over their nuclear programmes.

Though unapologetic about having taken aim at what he dubbed the “axis of evil” in his 2002 State of the Union speech, Bush has toned down his rhetoric on Iran and North Korea and tempered expectations for a quick solution.

Bush, who has resisted setting a timetable for US withdrawal from Iraq, has already made clear he expects future presidents will have to decide on any final removal of American forces from the country.

Even as Bush tries to stave off lame-duck status as he nears the end of his term in January 2009, hardly anyone expects troubles with Iran and North Korea to have faded either.

“It’s the legacy of this administration to the next. It’s a bit of a mess,” said Shirley Anne Warshaw, a political scientist at Gettysburg College in Gettysburg, Pennsylvania. — Reuters