Tony Blair has backed Britain launching airstrikes against ISIS in Syria, warning the whole of Europe must confront the growing terror threat at 'home'.

The former Prime Minister was criticised in the Commons this week for the legacy of his disastrous invasion of Iraq, which many MPs blamed for their opposition to new military action.

But in a speech in Washington, Mr Blair said leaders must 'learn the lessons' from the conflicts since 9/11 but warned support for ISIS stretches 'deep into parts of parts of Muslim societies'.

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Tony Blair has backed Britain launching airstrikes against ISIS in Syria, warning the whole of Europe must confront the growing terror threat at 'home'

Speaking at the Library of Congress in Washington DC, Mr Blair warned that a continued failure to recognise the scale of the challenge would lead to terrorist attacks 'worse that those in Paris'.

Referring to ISIS, also known as Daesh, Mr Blair said: 'Of course a large majority of Muslims completely reject Daesh-like jihadism and the terrorism which comes with it.

'However, in many Muslim countries large numbers also believe that the CIA or Jews were behind 9/11.

'Clerics who proclaim that non-believers and apostates must be killed or call for jihad against Jews have Twitter followings running into millions.

'The ideology has deep roots. We have to reach right the way down and uproot it.'

The speech came a day after a crunch Commons vote which saw a majority of 174 MPs vote to extend Britain's military action in Syria.

Within hours, seven precision-guided 500lb Paveway bombs were dropped on ISIS-controlled oil fields during two separate raids by Tornado jets flying out from RAF Akrotiri, in Cyprus.

However, many MPs including those from Labour, criticised Mr Blair's case for war in Iraq and claims of 'weapons of mass destruction' for a lack of trust in politicians who advocate military action more than a decade later.

Mr Blair praised the decision to back airstrikes, saying that Europe needed to create the armed force capability to allow the continent to 'not just play our part but to lead'.

Wider strategy: The former PM said military action could only be used alongside other approaches to tackling extremism. Pictured, two RAF Tornados arrive back at RAF Akrotiri in Cyprus, after a bombing raid in Syria

'We have to educate our own citizens and those now coming to our countries on what our values and way of life mean, why they matter to us and why we will defend them to the last,' he said.

Mr Blair, who resigned from his role as Middle East peace envoy earlier this year, said 'force alone will not prevail and that the Islamist ideology also has to be confronted'.

He said 'we should learn the lessons of the whole period from 9/11 to today' and try to forge a new approach to foreign policy which recognises the need for an 'active policy of engagement'.

Risk: Mr Blair warned that a continued failure to recognise the scale of the challenge would lead to terrorist attacks 'worse that those in Paris'. Pictured, the aftermath of one of the terror attacks in the French capital

He outlined a five-point plan which also included supporting academics and theologians who were tackling extremism, and seeking a wider engagement in diplomacy in the region.

But he added: 'This is a battle we will win. There is no doubt in my mind of that. From one corner of the world to the other, the overwhelming majority of people want to live in harmony and peace.