Jeremy Corbyn has drawn a parallel between maintaining communications with the IRA and finding a solution to Islamic State’s violence in the Middle East.
The Labour leader said governments in the region were already “in touch” with IS, which he compared to the “back channel” that existed between the British government and the IRA during the Troubles in Northern Ireland.
He said: “The British government maintained a channel to the IRA all through the Troubles. I don’t condemn them for that, I don’t condemn them for keeping a back channel to the Taliban,” he told BBC1’s The Andrew Marr Show.
“There has to be a route through somewhere. A lot of the commanders in ISIL (another name for IS) - particularly in Iraq, but also in Syria - are actually former officers in the Iraqi army.
“Dialogue is perhaps the wrong word to use, but there has to be some understanding of where their strong points are, where their weak points are, and how we can challenge their ideology.
“I believe that the neighbouring governments in the region are in touch. Look at the way in which there has been some degree at times of prisoner exchange, hostage exchange – things like that. We have got to bring about a political solution in Syria.”
During a wide-ranging interview, Mr Corbyn appeared to suggest that a Labour government could retain the Trident nuclear deterrent, but that the submarines would be put to sea without their nuclear warheads.
He also called for a “sensible dialogue” with Argentina over the future of the Falkland Islands and pledged to repeal the Conservative laws outlawing sympathy strikes.
On Trident, while he reiterated his long-standing opposition to nuclear weapons, he pointed out that the submarines could be deployed without their nuclear warheads on board.
“They don’t have to have nuclear warheads on them. There are options there. The paper that (shadow defence secretary) Emily Thornberry has put forward is a very interesting one, deserves a very good study and read of it,” he said.
“I hope that there will be a serious and mature response to what is a very serious and hopefully mature debate about the nature of security and insecurity, the nature of the way in which we protect ourselves against insecurity and we bring about a more secure world as a result.”
On the Falklands, while Mr Corbyn said the islanders should have an “enormous say” in any discussions with Argentina, he stopped short of saying they should have a veto over any new arrangements.
“I think there has to be a discussion about how you can bring about some reasonable accommodation with Argentina,” he said.
“It seems to me ridiculous that in the 21st century we’d be getting into some enormous conflict with Argentina about the islands just off it.
“Yes, of course the islanders have an enormous say in this. Let’s bring about some sensible dialogue. It happened before, I’m sure it can happen again.
“They have got a right to stay where they are, they have got a right to decide on their own future and that will be part of it. Let’s have that discussion, and let’s not set agendas in advance.”