Leading article: A suitable case for diplomacy

This is a vital distinction. The botched invasion of Iraq has sullied the name of the United States around the world. The US is simply not trusted when it acts unilaterally in the Middle East. And Syria - a long-standing target of the Bush administration - is a sensitive subject. If yesterday's resolution were handled clumsily, it would have had the perverse effect of strengthening the Syrian regime in the face of perceived US aggression. Other Arab states would have felt the need to come out in support of Syria in the face of American bullying. But the US -wisely - sought to build a consensus on the Security Council over the need for action over the murder of Hariri. Agreement was achieved. Now it will be difficult for the Syrian regime to ignore the will of the UN without tough consequences.

There are dangers in pressuring the Syrian regime, regardless of how it is done. It is unclear how much power is invested in the young President Bashar Assad. His removal could result in worse coming forward. And the invasion of Syria's neighbour to the east has radicalised the whole region. The extent of Islamic fundamentalism in Syria is unknown. But after decades of brutal repression - particularly by the late President Hafez al-Assad - there is a risk that destabilising the regime from outside could result in Syria, like Iraq, rapidly descending into bloodshed.

Yet the exertion of calculated pressure - through a UN criminal investigation - is the only way to proceed. Yesterday Syria announced its own investigation into the death of Hariri. This is likely to be a sham, but it at least shows the regime recognises that it cannot flout the will of the international community. This is encouraging. So is the fact that the Syrian deputy foreign minister is on a tour of the Middle East in a bid to rally Arab support. There are signs that, in sponsoring the assassination of Hariri, the Syrian regime over-reached itself.

This is a chance to bring Hariri's murderers to justice. And if, as suspected, they are senior figures in the Syrian government, this also becomes a chance to bolster the reform of Syria from within. But the situation must be handled with patience - and diplomacy.