The Paris attacks may mark the metamorphosis of Islamic State group (ISG) into a terrorist network with global reach, capable of mobilising local-born radicals in Western Europe to launch mass casualty attacks in urban centres.
With world leaders arriving, December's COP21 climate conference in Paris will become an international expression of solidarity with France.
European security services will argue successfully for greater powers and resources.
Paris may face more domestic calls to review its warm relationships with Gulf states, given their role sponsoring radical Islamist groups.
Previously possible changes to France's defence and foreign ministers in coming months may now be in doubt.
Muslim and refugee sites across Europe will be at risk of reprisal attacks.
