In military terms, Britain's decision this week to launch air strikes against the Islamic State in Iraq and Syria (ISIS) changes little: Its air squadron operating over Syria will account for only 8 per cent of all the air sorties undertaken by the US-led international coalition. Still, the British move is politically significant.
The US has complained for some time that the Europeans are not shouldering their proper share of the responsibility for their own security; after all, Europe is closer to the Middle East than North America is. That criticism has now been answered: Britain and France are putting greater resources into the fight against terrorist hubs in the Middle East. Even Germany, hitherto reluctant to fire a shot in anger, is pledging new military resources.
The British decision to contribute to the air strikes on Syria, reached after an anguished political debate in London, has also put to rest longer-term US worries about the reliability of what used to be the United States' most stalwart European ally.
And Britain's entry into the Syrian fray has also given the anti-ISIS operation a more precise focus:
It is instructive that its first air strikes were directed against ISIS oil extraction and refining installations, which provide the terrorist group with most of its revenue.
The main question now is whether the expansion of the anti-ISIS alliance will lead to a more comprehensive plan which not only aims to hit terrorists, but also seeks to evict them from their current hideouts.
The British hope that this can be achieved by assisting local rebels in turning their fire against ISIS. US and British special forces are on the ground providing training, and more are on their way.
The strategy is undoubtedly correct: A ground offensive supported by an air campaign offers the best opportunity to defeat the terrorists. But it also increases the danger of miscalculation.