| Alex Salmond, Scotland's First Minister, is a major advocate of independence from Britain [GALLO/GETTY]
Britain once ruled a vast empire from India to Singapore and South Africa, but its own borders are now being threatened.
The Scottish National Party, which won last May's Scottish election, has pencilled in autumn 2014 as the date for a referendum on independence. Voters will be asked whether Scotland should secede from the UK and become the world's newest independent state.
It is likely to be the most important democratic decision that many Scots will make.
Scotland's First Minister, Alex Salmond, on a visit this week to the World Future Energy Summit in Abu Dhabi, told Al Jazeera, "I want Scotland to be independent because independence is the natural state for most nations around the world - not being independent is the exception."
A concern for Cameron
British Prime Minister David Cameron has good reason to be concerned.
It has become a common joke that his ruling Conservative Party has fewer Scottish MPs than the number of giant pandas in Edinburgh Zoo. (There are two pandas - just one Tory.)
His government's austere programme of spending cuts is beginning to bite; the Scottish Nationalists are counting on them becoming even more unpopular as the referendum approaches.
If Salmond gets his way and the Scots vote for independence, the UK will lose 90 per cent of its oil and gas reserves in the North Sea and almost half its land mass.
Sir Malcolm Rifkind MP, who served as Britain's Defence and Foreign Secretary, told Al Jazeera, "I have no doubt that if Scotland became a separate state the perception would be that the UK was a much diminished country."
UN Position at stake?
One of the major issues that Rifkind fears could be at stake is Britain's status as a permanent member of the UN Security Council.
The composition of the Council reflects the world as it was in 1945, rather than today. There is no longer any logical reason for Britain to be a permanent member instead of countries with stronger economies, like Germany or Japan, or emerging powers like India or Brazil.
Rifkind, who is himself a Scot, said that if Scotland declares independence, "It would certainly open up the question of permanent membership of the Security Council in a way that would be quite awkward for the UK." In the understated language of British diplomats, "quite awkward" almost nearly always means "absolutely bloody awful".
Where will the submarines go?
If Scotland declares independence, it is also likely that the UK will be forced to find a new home for its four Trident submarines, which are currently based at Faslane, around 25 miles from Glasgow.
The Scottish National Party detailed the matter in their election manifesto: "Our opposition to the Trident nuclear missile system and its planned replacement remains firm - there is no place for these weapons in Scotland."
Salmond confirmed to Al Jazeera that "an independent Scotland will not have nuclear weapons, and after we become independent Trident weapons of mass destruction will no longer be based in Scottish waters."
Defence officials are already looking at contingency plans to transfer Britain's nuclear deterrent to England if Scotland declares independence, but England does not possess a deep-water port with the same secluded and easy access to the North Atlantic. And even if a suitable site could be found, developing a new port would be phenomenally expensive.
Professor Malcolm Chalmers, Research Director at the Royal United Strategic Institute, predicts that the nuclear issue could cause serious tension between London and Edinburgh. "An independent Scotland would come under very strong pressure to retain the base for a decade or more - just as the Russian Navy has stayed in Ukraine, or the Royal Navy stayed in Ireland until 1938," he told Al Jazeera. "Certainly, it is hard to imagine that London will be sympathetic to Scotland's economic demands - including EU membership - if Scotland insisted on rapid removal of its submarine bases."
If the two governments couldn't reach a deal, it is a real possibility that the UK could be left with no operational nuclear deterrent because the submarines could not be safely berthed.
A foreign policy of its own
Up until now, the SNP Government's most important foreign policy move, which drew ample international attention and criticism, was its decision to free the man convicted of the 1988 bombing of Pan-Am flight 103 over Lockerbie, which killed 270 people.
Abdelbaset al-Megrahi was released from prison and sent home to Libya on compassionate grounds after he was diagnosed with terminal cancer.
The ability to continue formulating its own policy is also a factor motivating Scotland's drive independence.
Scotland's First Minister was a ferocious critic of Britain's involvement in the US-led invasion of Iraq. He told Al Jazeera that "one of the key advantages of independence will be the fact that Scotland will no longer face having its servicemen and women participate in illegal wars like the disastrous invasion of Iraq, which was pursued without any proper authorisation from the United Nations."
This week's visit to Abu Dhabi is his second visit to the Gulf region in recent months. He believes Qatar is a good example of what a small country can achieve if it is given a global platform.
"I was hugely impressed during my first visit to Qatar as First Minister late last year," he told Al Jazeera. "Qatar and Scotland share many similarities when it comes to our experiences in the energy sector - both in terms of oil and gas and in our common desire to be pioneers of renewable energy."
A historical decision
The date of the referendum, in Autumn 2014, coincides with the 700th anniversary of the Battle of Bannockburn. This was the confrontation depicted in the closing scene of Mel Gibson's film Braveheart in which the English army is finally defeated.
Both sides will appreciate the historical significance of this fact.
Rifkind said that the campaign to keep Scotland as part of the UK will be fought very hard and support for Scottish independence will fall as the issues are scrutinised.
If he is wrong, it is quite possible that the UK will find its voice lowered in world affairs. Alongside it will be a newly independent Scotland, which may take a very different view on many issues.
Follow Andrew McFayden on Twitter: @apmcfadyen