The US has decided to go its own way on several issues, including missile defence

This, for the moment, appears to be more of a difference in tone than real substance. It is unlikely, for example, that Mr Clinton would have dealt any differently with the current crisis.

But tone is important in foreign policy, and the Chinese, Russians, even the Europeans, have all reacted sharply to what appears to be a more prominent "unilateralism" in Washington.

Unilateralism defined

This unilateralism is best defined as a conscious decision to put America first, even if there is a diplomatic price to be paid.

Whereas Mr Clinton became known as a determined consensus and alliance builder, Mr Bush has signalled on a number of issues that the US is prepared to go it alone, even if it puts noses out of joint in other countries - friend or foe.

• Mr Bush has put great store by a National Missile Defence System, which the Chinese and Russians both oppose strongly, and the Europeans are wary of, to say the least.

• He has made clear that he will not implement the Kyoto treaty on the environment, a decision that has upset all the other signatories.

• Mr Bush has also publicly differed with the Korean President Kim Dae-jung about how best to deal with North Korea.

Splits in the administration

In many cases, though, the details of US foreign policy have still to be worked out.

Much is "under review" - in particular, policy towards the Koreas, financial support for Russia, and energy policy, which will have a direct bearing on the Kyoto Protocol.

Colin Powell's reversal on key policy issues shows the state of play of US policy abroad

During this review stage there is plenty of opportunity for the central figures in the administration to try to push the policies in their direction.

Already there are some distinct differences emerging.

Twenty-four hours after saying that the Bush administration planned to pick up negotiations with North Korea where Mr Clinton had left off, Secretary of State Colin Powell reversed himself, telling reporters that President Bush was reviewing the policy and did not intend to resume negotiations in the near future.

There are also two schools of opinion in Iraq, with Mr Powell travelling the Middle East to push a policy of revising and re-applying sanctions, while the Defence Secretary, Donald Rumsfeld, has made clear that he has little time for sanctions.

He would prefer the overthrow of Iraqi President Saddam Hussein, through support for opposition groups.

Blunt approach

On National Missile Defence, Mr Powell has emphasised the need to get the Europeans on board, and to re-negotiate the Anti-Ballistic Missile treaty with Russia, which currently bans missile shields such as that proposed by Mr Bush.

The rest of the world will be taking notes as this new administration begins to fill in the gaps on foreign policy

President Bush and the Pentagon have both indicated that the ABM has outlived its usefulness, and should not obstruct America's national defence priorities.

The president's blunt approach to Moscow was also reflected in his swift expulsion of 50 Russian diplomats from Washington, whom he accused of spying.

The Russian foreign minister has yet to visit Mr Powell in Washington - and Mr Bush has shown little urgency in arranging a meeting with Russian President Vladimir Putin.

Cool to China

On China though there is a greater sense that the administration is singing from the same songbook - although the defence secretary has been notable for his low profile during the current standoff.

Despite the smiles, Mr Bush's meeting with Qian Qichen was reportedly cool

He is perhaps wary of reflecting the Pentagon's deep anger about the episode.

By all accounts, Mr Bush's meeting with the Chinese Vice Premier Qian Qichen earlier this year was a cool one, which focused on their many differences including human rights, Taiwan and missile defence.

The US has been working for a resolution condemning China's human rights record at the UN Commission on Human Rights in Geneva.

It is also protesting against China's detention of two US-based academics, and considering the sale of advanced weaponry to Taiwan.

Just how the furore over the collision of the American surveillance plane and the Chinese fighter is eventually resolved may prove to be a useful indicator of the approach that President Bush ultimately intends to take on China.

Mr Bush has already indicated that China could well become the most important on his foreign policy agenda.

The rest of the world will be taking notes too, as this new administration begins to fill in the gaps on foreign policy.