Speaking at York College Mr Corbyn said that “the war on terror has manifestly failed”.
He said: “For far too long, our country’s leaders have made the wrong calls on our security.
“Their mistakes in no way absolve terrorists of blame for their murderous actions – the blame lies with the terrorists, their funders and recruiters.
“But if we are to protect people, we must be honest about what threatens our security.
“The threat of terrorism cannot and should not be reduced to questions of foreign policy alone, but too often the actions of successive governments have fuelled, not reduced, that threat.”
Mr Corbyn added that he “warned against the invasion and occupation of Iraq” yet the UK is “still living with the consequences today”.
He continued: “Britain should not have joined that conflict which has, as a result, created a vast ungoverned space, that has contributed to misery in the region and made us less safe here in this country, and indeed many other parts of Europe.”