U.S.: Bush Italy Visit Highlights Unity, But Amid Widening Differences Over Iran, Russia

But the smiles and bear hugs won't be able to mask the fact that when it comes to substance, the two sides have increasingly divergent interests.

"The problem is that when you look at specific policies, and in particular the policy toward Russia and [Italy's] commercial policies, you realize that actually Italy is a very different country from the U.S.," says Giovanni Gasparini, a senior fellow for security and defense issues at the Rome-based Institute of International Affairs. "So it has necessarily different aims and different interests to protect."

One point of difference is Russia.

It's no secret that Berlusconi has long cultivated ties with former President Vladimir Putin and forged close links with the Kremlin. Italy's prime minister has been keen to deepen commercial ties with Russia -- especially in the oil and gas sector.

As Gasparini points out, Berlusconi's tango with Putin didn't bother Washington when Bush saw him as an ally. But the recent souring of relations between Moscow and Washington means Berlusconi is now out of step with the U.S. leader.

On another major issue, Iran, Rome and Washington also seem to share little in common.

Italy is keen to join the five permanent members of the UN Security Council plus Germany in negotiating with Tehran about giving up its uranium-enrichment program. Bush and Berlusconi are certain to discuss the issue.

But Gasparini says Italy's interest in joining the group may have more to do with protecting Rome's commercial interests, than supporting harsher measures against Tehran. That's because Italy recently surpassed Germany as Iran's largest European trading partner.

On yet another key issue, Afghanistan, Italy may offer the Bush administration limited assistance. But the United States is unlikely to get the concession it really wants.

Washington would like Italy -- and other European NATO members that have forces deployed in northern Afghanistan -- to send or redeploy soldiers to the volatile south, to help combat the Taliban.

Italy currently has more than 2,000 troops in the north and Gasparini says Rome is likely to offer some of those troops for limited, individual missions in the south. But a permanent redeployment is not in the cards.

The Italian government seems to have been chastened by its experience in Iraq, when it deployed some 3,000 troops to the country to aid the U.S. effort -- going against public opinion at home.

Berlusconi was later forced to withdraw those troops and the whole episode cost him politically.

Following his recent reelection, he is unlikely to go against such public opinion again -- which is strongly opposed to increasing Italy's foreign military involvement.

To sum up, expect lots of smiles and jokes during Bush's public appearances with Berlusconi. But Italy's leaders will have their eye firmly on their own perceived interests.