Taiwan's military exercise, the aim of which was to simulate an invasion by mainland China, can only add to the tension between the two old adversaries.

There is no doubting the seriousness of the exercise - and the message it is meant to send out to the authorities in mainland China.

Thousands of personnel awere involved and live ammunition was employed.

What is more, the exercise went ahead despite the row between the Americans and Chinese, who have so far steadfastly refused to return the US spy plane that was forced to land on a Chinese military airfield after a mid-air collision with a Chinese jet.

That led to a 12-day stand-off between the US and China, before the crew were allowed to return home. However, the political picture is made more complex, as the Chinese Government strongly objects to the arms deal between the US and Taiwan.

Bargaining chip?

Taiwan's military exercise added to the tension. But it believed it has no alternative.

"The number one potential threat from Taiwan's point-of-view actually is from men in China," said Michael Tsian, a member of parliament in the country's governing Democratic Progressive Party. "They have never said they will give up invasion by force.

Taiwan is hoping for hi-tech weapons from the US

"Therefore, from a Taiwanese point-of-view, we have to prepare ourselves for defending Taiwanese sovereignty."

Shortly before Taiwan's exercise got under way, the Americans were negotiating with the Chinese to try to get the US spy plane released. Some analysts have suggested China is keeping the plane to negotiate with the US over the offer of American weapons to Taiwan.

Richard Boucher of the US State Department simply said the aircraft should be returned.

"We think it's quite clear that it should be returned," he said "We're looking for our airplane back and we've proposed to them how to do it.

"At this point, unless we hear something from them, I don't have any way of explaining that to you."

But seen from Taiwan, there is no reticence in publicly pointing to the underlying problems in the China-Taiwan-US relationship - and how they can be resolved.

The focus point to defuse this tension actually has to come from China - not from Taiwan," said Mr Tsian. "Actually, we are not trying to invade China - no.

"We are trying to [bring about] peaceful coexistence between Taiwan and China. The problem is the Chinese side.

"The last three years, they have set up more than 300 missiles against Taiwan, which are located on the Chinese coast."

Just routine?

On the surface, there seem to be all the elements for a worrying escalation of tension in the triangular US-China-Taiwan relationship.

But Professor John Copper, an adviser to the Reagan administration and a long-standing expert on US-China relations, believed the Taiwanese military exercises were "quite routine".

"They do come at a rather sensitive time, in view of the surveillance plane that was landed in China and also the talks that are going on between US and Chinese representatives at the moment," he said.

"I think they want to negotiate the return of the plane and perhaps get something from the United States - perhaps a reduction in the [surveillance] flights that will be done.

"The US Government is of course saying the flights will continue."