By Jon Leyne BBC State Department correspondent

There were no gasps of surprise in the Security Council. Nobody rocked back in their chairs, in amazement at the revelations.

This effort to hide things from the inspectors is not one or two isolated events Colin Powell

Click here for key points of briefing

Instead, Colin Powell's presentation on Iraq was listened to in a respectful silence.

The drama was muted. This was not a replay of the historic confrontation during the Cuban missile crisis, when US ambassador Adlai Stevenson demanded answers from his Soviet counterpart.

But it could still be the turning point between peace and war.

Multimedia trick

As so often, Mr Powell showed no hint of the pressure he must have been under as the world watched.

He breezed into the council chamber, smiling, laughing and shaking hands with fellow ministers.

At one point he even blew a kiss across the council table to his Spanish counterpart, Ana Palacio.

Then as the presentation began, the Secretary of State quickly brought out one of his multimedia tricks.

It was audio tape the Americans claim is an intelligence intercept between Iraqi officials. They discuss a "modified vehicle".

"We evacuated everything. We don't have anything left," says one of the Iraqis.

Then Mr Powell went on to produce satellite photographs, evidence from defectors or from other unnamed "sources".

Terror connection?

All of that shows the product of what sounds like a pretty lively battle within the administration over how much information to release.

Russia offered to lend the Americans a plane

Interestingly CIA director George Tenet walked into the UN with Mr Powell, then sat immediately behind him in the Security Council.

The message was clear - the intelligence community agreed these secrets were safe to release.

It was a multi-layered speech that worked through the American allegations piece by piece.

Colin Powell detailed Iraqi attempts at deception, Iraq's weapons programmes themselves - then, perhaps, most controversially, Baghdad's alleged links with al-Qaeda.

That last element will probably come in for the most criticism.

It took Mr Powell around 20 minutes to trace the rather tortuous chain of connections that the Americans claim exists between Baghdad and Osama Bin Laden.

No smoking gun here, more a chain of logic even Sherlock Holmes would have problems unravelling.

Squirming

And the immediate reaction was not promising.

With Colin Powell glowering at him, Iraqi ambassador Mohammed al-Douri said there was no new information, just unnamed sources and unknown sources, "assumptions and preconceptions that all fit into America's known objective".

Russian Foreign Minister Igor Ivanov, seemed almost to tease the Americans.

The presentation showed the need to strengthen the inspection process, he said.

He even offered a Russian plane to help - exactly what the Americans do not want, as they seek to prove the inspection process is broken beyond repair.

Mr Powell seemed to squirm in his seat as he heard the bad news.

French Foreign Minister Dominique de Villepin also seemed wedded to the continuation of inspections.

He suggested a tripling of the number of inspectors, the establishment of a new co-ordination centre, more surveillance aircraft, extra regional offices for the inspectors.

Inevitability

Certainly this was not a day on which the world changed. The true believers on both sides of this argument will not have been converted.

And yet Colin Powell is probably happy with his day's work. Waverers may have been swayed his way.

Even the French were moved to stress the urgency of Iraq's compliance with the Security Council's demands.

The American skill throughout this crisis has been to build an aura of inevitability.

Step by step they have made it appear as if war with Iraq is unavoidable.

So the lasting message from the United States - the war is going to happen, be with us or be irrelevant.