Europe must develop a strong foreign and defence policy to enable it to deal with crises like Ukraine, Tony Blair has said.
The former prime minister said that events in Ukraine and the Middle East had shown that Europe still remained "completely dependent" on the United States.
Speaking to the Progress centre-left think-tank in London, Mr Blair was also strongly critical of David Cameron's handling of the issue.
He said that Conservative policy on the issue was being driven by internal party considerations rather than the national interest, and he expressed dismay at the "stranglehold" Ukip had achieved over the debate on Europe.
Mr Blair said that it was "absolutely essential" that the United States and the EU delivered a "strong and united message" to Russia over Ukraine.
At the same time he stressed the importance of Europe developing the capacity to deal with problems that arose on its own doorstep.
"There is such an urgent need today for Europe to have a strong foreign policy and indeed a defence policy," he said.
"If you look at any of the crises that are happening, whether it is in Syria on the doorstep of Europe, Libya on the doorstep of Europe, Ukraine on the doorstep of Europe, we are completely dependent on the United States of America.
"I'm a great fan of the US, and I think it's important we remain strong allies of the US, but we've got to develop in Europe the capability to handle the problems on our own doorstep."
Mr Blair expressed concern over the growing influence of Ukip and David Cameron's promise to stage an in/out referendum on Britain's membership of the EU by the end of 2017 if the Conservatives are returned to power in next year's general election.
"A lot of policy on Europe is being driven by internal Conservative Party considerations, not the national interest," he said.
"I can't tell you how dismayed I get that Ukip have any sort of stranglehold on the policies and direction of our country because they represent a backward force that does not offer anything for the future of this country."
While Mr Blair said that he did not believe people would vote to leave the EU, he said that the prospect of a referendum would create damaging uncertainty for business and for the country at large.
"The British people can sometimes have certain prejudices but they get shocked if their political leaders start sharing them. I think most people when they really sit down and think about it, they know it's not sensible to get out of Europe," he said.
"If the Conservatives are re-elected, that's two years of uncertainty with this thing hanging over us. And two years by the way, when the every waking thought of the guy in charge is going to be 'How do I avoid this car crash'."
Ukip deputy leader Paul Nuttall said: "How utterly astonishing that Tony Blair, the warmonger, after stating that he wants the EU to have a stronger foreign and defence policy, should then call Ukip backwards?
"He must be bored without foreign wars to wage and has totally forgotten that the sort of pan-continental military he would no doubt love to rule would not be out of place in Cold War USSR.
"No Mr Blair, Ukip is forward-thinking, not backwards. We want a nimble and free United Kingdom, with strong ties across the entire globe, not a glacially-paced, economically stagnant, outmoded continental block that is not fit for purpose in the 21st century.
"Our view is that of international trade, not myopic regional warfare underpinned by stifling interdependency."