More than 200 cruise missiles were fired against Iraqi targets during the first night of the US-led strikes against President Saddam Hussein's regime.

Jonathan Marcus: "An effective inspection regime is now unobtainable"

The tempo of the operation is expected to be reduced during the daylight hours, with a resurgence once night falls again.

But the initial attacks signal a significant shift in US policy towards Iraq.

Washington until now has always seen force as a means to encourage Iraqi compliance with United Nations Security Council resolutions.

Effective inspection unobtainable

Indeed, the threat of force has been repeatedly used to try to sustain a meaningful inspection regime to ensure that Iraq does not seek to re-build its nuclear, chemical and biological weapons programmes.

Air traffic controllers on the USS Enterprise guide the missiles

But in embarking upon what looks to be a sustained attack against Iraqi targets, the US and Britain seem to have decided that an effective inspection regime is now unobtainable.

Instead, military force is being used, not only to punish the Iraqi regime for its non-compliance, but also to destroy as much of the existing Iraqi weapons infrastructure as can be found.

High-risk strategy

Some of the main pillars of the Iraqi regime, like the special Republican Guard, President Saddam Hussein's most loyal units, may also be targeted.

They are thought to have a key role in the huge deception operation that the Americans insist has kept significant parts of Iraq's weapons programmes just beyond the inspectors reach.

It is a high-risk strategy, ending even the appearance of consensus within the UN Security Council.

Despite careful targeting, significant Iraqi casualties are possible.