Forget the media labels "far-left" or "hard-left", in terms of economic policy is the new Labour leader any more to the left than say George Osborne or Boris Johnson are to the right?
Jeremy Corbyn's anti-austerity ideas are in many ways quite conventional Keynesian economics not that far removed from those advocated by the Nobel Prize winning economist Paul Krugman.
Where Corbyn holds views that are a more obvious break with both past British governments and his own Labour Party is in foreign policy.
Barring the three years when Michael Foot led the party in the early 1980s, since 1945 Labour has been led by Atlanticists who see close relations with the US, the possession of nuclear weapons and membership of NATO and the EU as central to Britain's place in the world.
Corbyn has been compared with Foot, but it's hard to imagine him making the passionate speech Foot did supporting British military action over the Falklands in 1982. His role in the Stop The War coalition opposing military interventions abroad and his advocacy of withdrawal from NATO make comparisons with George Lansbury, the pacifist who led the party between 1932 and 1935, more apposite.
And even if he never makes it into government, as Leader of the Opposition his approach to foreign policy matters.
Through parliamentary debates and votes he can have a direct influence on policy as his predecessor Ed Miliband showed when he opted to vote against military action in Syria in 2013.
Also, as the main spokesperson for the UK's main opposition party his positions on the international issues of the day will influence perceptions of Britain in the world.
The three areas where Corbyn is likely to have influence in the next few years are the main ones in Prime Minister Cameron's in-tray: the renegotiation of Britain's EU membership and subsequent referendum; the decision whether or not to replace Britain's Trident nuclear weapons; and if British forces should join the US-led military action against Islamic State in Syria.
During his leadership campaign, Jeremy Corbyn told journalists he had voted to leave what was then the EEC in the 1975 referendum and he sent out mixed signals about his approach to the next vote, which could be held as early as next year.
But since his victory Corbyn's position has come under intense scrutiny and he has committed to campaign for Britain to remain a member.
As he laid out in a Financial Times Op Ed, his misgivings about today's EU are based on its approach to economic policy which he identifies, quite correctly, as dominated by neo-liberal ideas. He wants to see greater protection for social and employment rights and will push Cameron to include these in his renegotiation.
This is counter to the agenda the Prime Minister is currently pursuing. So if Cameron gets most of what he wants in his renegotiation and recommends a ''Yes" vote, it could put Labour in a tricky position.
Corbyn's FT article gives a clue to his likely approach to the vote. He implies Labour would also campaign for a "Yes" while at the same time promising to renegotiate a better deal when they return to power.
If that is the position he takes, it risks not only being a confusing message, but is also likely to be regarded as unrealistic given Britain's EU partners, having just finished a painful renegotiation with Cameron, will be highly unlikely to agree to an incoming Labour government's request for yet more special treatment for the UK.
On Syria, Cameron has already announced a drone was used to kill two British citizens fighting with IS who, he said, were a direct threat to the UK, but full-scale air strikes would have to get parliamentary approval.
Here Corbyn will have some sway.
If the government opts to take action, the Labour leader has made clear he will oppose it. The SNP would also vote against. So the result would hinge on how many Labour MPs broke ranks with their leader to back Cameron and how many Tories rebel against the government - in 2013, remember, thirty of his own MPs defied the Prime Minister on Syria. The final tally could depend on how well Corbyn argues the case against action to the House of Commons.
Then there's the final decision on the replacement of Trident, expected to be made next year.
When Britain opted to replace Polaris with Trident in 1980, Cold War tensions were high following the Soviet intervention in Afghanistan and public opinion was not persuaded by opponents like the Campaign for Nuclear Disarmament and other activists.
This time public opinion seems more divided and polls where the people are told how much it would cost have shown majorities against replacement.
Cameron almost certainly has the votes in parliament, including some on the Labour side who would defy Corbyn if he whips the vote. But the platform the Labour leader now has to oppose the decision could help increase public opposition by galvanising a wider debate on the utility and affordability of nuclear weapons as well as the benefit Britain gets out of having them and could potentially reap from giving them up.
All told, if the new Labour leader can broaden the appeal of his views on Britain's role in the world among his parliamentary colleagues and the public, he could have an unexpected influence on UK foreign policy.