Does the UK remain a world power?
Is the UK's role on the world stage a decades-long story of managed decline, including the orderly withdrawal from a once vast empire?
Or is it the story of a medium-sized power whose standing in the world reflects the new global reality?
Which way should we face: towards Europe, or US?
The US Secretary of State Dean Acheson in 1962 described the UK as a nation which had lost an empire, but had yet to find a role.
Others, such as former Foreign Secretary Douglas Hurd preferred the idea that the UK "punches above its weight" in world affairs.
And in the wake of the 11 September terrorist attacks on the US, Tony Blair put forward his own view of Britain's place on the international stage: if no longer a super-power, then at least a force for good in the world.
Well, the debate about the UK's role in the world goes on. Or does it?
Not an election issue
The first television debate of the UK election campaign led some people to ask why there was not a single question on foreign policy.
The explanation might be that not every topic can be squeezed in during a short time.
But in a curious way it was a taste of things to come in that foreign policy - defence spending and Trident aside - hasn't really featured in a big way during the election campaign.
This is puzzling at a time when the world is engulfed in multiple crises.
There are military conflicts in Syria, Iraq and Yemen; Libya is falling apart; and in the very heart of Europe, the battle over Ukraine continues.
Policy makers have no real idea how to handle a resurgent Russia or how best to counter the growing power of China.
But what is the UK's role, if any, and more to the point, even if it wanted to do something, what is realistic and feasible at a time of shrinking budgets?
In some ways the Hurd remark about Britain punching above its weight frames much of the ongoing debate.
The UK, the plucky nation that once ruled an empire, is still at the top table, with a bigger voice and role than its current global position might merit.
In this narrative, the slow withdrawal from being a global superpower has to be tempered with other examples of the UK's power and might.
It highlights Margaret Thatcher and Tony Blair as big players on the international stage, standing shoulder to shoulder with the US on all the big questions of international policy.
Those on this side of the argument - let's call them the foreign policy activists - believe this strength is now slowly eroding and that we are witnessing a clear decline in the UK's standing, a nation, they say, ghosting into the shadows.
Everywhere across the globe, as the crises and wars multiply, the UK is reduced to being a bit-part player.
Look at the eurozone stand-off with Greece over its debt, they say: the UK doesn't have a voice and can't play a part.
They point to German Chancellor Angela Merkel's recent attempts, alongside France, to rein in President Vladimir Putin over Ukraine. Again, they ask, where was the UK?
They add to this roll call the decision of Parliament back in 2013 not to support putative American action in Syria as another example of abdication of leadership in foreign policy.
Other examples are cited such as the Iran talks, where they claim France now has a bigger voice at the table than the British.
In other words, big and important foreign policy issues in which the UK might once have stepped up and led the way but no longer.
The alternative view goes something like this. The UK public is exhausted by military intervention in the wake of the conflicts in Iraq and Afghanistan.
The more recent chaos in Libya, following Western military action to overthrow Col Muammar Gaddafi, say some, has only added to this sense of public scepticism.
The UK needs to get real, according to this viewpoint.
It is a middling power, at best, with other priorities at this time.
It doesn't and cannot straddle the world stage, nor should it want to. It must pick and choose its fights carefully for a different day and age.
So, it currently stands shoulder to shoulder with the US in the fight against IS and is party to the military action to push back IS in Iraq.
It still carries a big voice at the UN where it has a prized permanent seat on the security council.
It is a senior member of the EU and a founding member of Nato, and its voice still counts for a great deal in the corridors of power.
And then of course there is the so-called Special Relationship with the US. The UK, in this view, is a wise friend.
The UK, they argue, is better off pursuing its foreign policy goals via other means such as trade and soft power.
These voices point to the post-war success of Germany and Japan as big and important economies.
These countries, it is argued, show that trade and economic success is a better and more productive route to global success than mere military posturing.
- Respected foreign affairs policy think tank, Chatham House and BBC Radio 4's The World Tonight programme host a debate on UK foreign policy at 13:00 on Thursday. On the panel are former US Assistant Secretary of State, James Rubin, Chatham House director Robin Nibblett, Timothy Garton Ash, from Oxford University, and author and historian Anne Applebaum. The programme will transmit a recording of the discussion on Friday and Chatham House will publish a transcript on its website.