LONDON (Reuters) - After the deadliest attack on Europe in over a decade, Britain said on Monday it would hire more spies while France called for better intelligence sharing and tougher controls on the EU's external borders against arms smugglers and Islamist militants.
Islamic State warned in a new video on Monday that countries taking part in air strikes against it in Syria would suffer the same fate as France - where at least 129 people died in Friday's bloodbath in Paris - and threatened to attack Washington.
With European Union governments faced with defending over 500 million citizens of the bloc from such well-planned attacks, Britain announced it would recruit an extra 1,900 spies.
"This is a generational struggle that demands we provide more manpower to combat those who would destroy us and our values," Prime Minister David Cameron said at a Group of 20 summit in Turkey.
The hiring will boost staff at Britain's domestic MI5 security service, MI6 foreign intelligence agency and the GCHQ eavesdropping centre by about 15 percent to around 14,600, likely to be a record number.
Cameron's government also plans to double spending on aviation security following the crash of a Russian airliner in Egypt last month, which Britain has said it believes was brought down by a bomb.
Western security sources and officials said the Paris attack indicated Islamic State was parading its ability to strike outside the Middle East with mass attacks against unarmed civilians. This also marked an escalation from the group's executions of hostages in areas it controls in Syria and Iraq.
"A year ago we were talking about them taking one or two Western citizens hostage, now we are talking about potentially much broader mass casualty attacks," a source in Cameron's office said.
Andrew Parker, the director general of MI5, said last month that the intensity of the threat against Britain was greater than he had ever experienced in his 32-year career.
Britain's current threat level is "severe", the second highest rating on a 5-level scale, meaning an attack is highly likely. Around 750 British militants have travelled to Syria.
"There is little doubt that there will be further attacks," John Sawers, the former head of MI6 said in an article published in the Financial Times on Monday. "Countering terrorism requires tight co-ordination of agent penetration, intercepts and bulk data analysis. Teamwork is vital."
While French citizens living in Belgium were among the Paris attackers, the possibility that one suspect may have posed as a Syrian refugee has reignited a debate about the EU's handling of the migration crisis.
The head of Germany's domestic intelligence services called for "orderly procedures" regarding the handling of the daily entry of thousands of asylum seekers in to the country, saying extremists could exploit the sometimes chaotic migration situation.
As the scale of the attacks became apparent, some opponents of European integration called for the scrapping of the Schengen agreement which abolished most border controls between 26 European countries.
France has called for an emergency meeting of EU justice and interior ministers to speed up and implement security measures already under discussion.
"Arms trafficking is one the things we need to fight if we are going to be effective in fighting terrorism," Interior Minister Bernard Cazeneuve said after meeting his counterpart from Belgium.
Cazeneuve also said EU governments and the European Parliament needed to reach agreement rapidly on a system to share airline passenger data, without watering it down.
Lawmakers have resisted endorsing the system, known as the Passenger Name Record, on the grounds it could infringe personal privacy.
Cazeneuve also said European countries needed to improve their intelligence sharing and ensure there are "systematic and coordinated controls" of the EU's external borders.
France reintroduced border controls even before the attacks to tighten security before international climate talks which Paris will host at the end of the month.
Additional reporting by Andy Callus, Leigh Thomas and Michael Holden; editing by David Stamp