CLAIMS by a leading academic that Brexit will soften American hostility to Scottish independence have been given a cautious welcome by SNP politicians.

However, one diplomat told the Sunday Herald that to even discuss it was to deal in “imponderables”.

Phillips O’Brien, Professor of Strategic Studies at the University of St Andrews, used a column in Thursday’s Herald to say that Britain’s waning influence in Europe after Brexit would deprive the US of its main benefit in the special relationship.

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In the article, the academic argued that defence policy “was perhaps the greatest handicap for the Yes side”.

“It was torn between supporting a vocal section of its electorate that was so anti-nuclear and unilateralist that it not only worried many moderate Scots, who consistently are pro-Nato, but also many of the UK’s closest European defence partners,” he wrote.

He went on say that for the US, “Britain’s most useful role has been its ability to play this leadership role in Europe” and “if forced to choose, America will always opt to work with the EU as a whole over a Brexit UK with an ever shrinking military”.

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US top brass are aware of the UK’s fractures, the professor claims, and “would not intervene nearly so much as before to try to convince Scots to maintain the status quo”.

“If the SNP and the Yes campaign develop their policies in a centrist, cooperative way, they could turn what was the biggest handicap in the last campaign into a possible plus. They could run on confirming Scotland’s commitment to European institutions and Nato.”

Stephen Gethins, who sits on the Commons Foreign Affairs Select Committee said Scotland could easily be the US’s way into the EU.

“Scotland’s relationship with the United States is always going to be an important one given important historic links between our two countries as well as the strong economic connections,” he said.

“The United States also has a strong interest in the European Union as President Obama outlined during the EU referendum. Scotland remaining part of the EU would provide a partner within Europe as well as bringing Scotland significant competitive and strategic benefits.”

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One former senior British diplomat was less convinced. Darren Burgess, who served as the Scottish Affairs Attaché at the British Embassy in Washington between 2010 and 2014, told the Sunday Herald: “The post-Brexit landscape is littered with so many giant imponderables. In the context of US facing its own watershed, it's currently difficult to envisage any obvious unintended benefits accruing to the UK or Scotland post-Brexit.”

It was in the June of 2014, when Barack Obama made a surprise intervention in Scotland’s referendum campaign. Appearing alongside David Cameron at an EU summit Obama said he wanted the UK to remain a “strong, robust, united and effective partner”.

He told reporters: “There’s a referendum process in place and it’s up to the people of Scotland.”

But he then added: “I would say that the United Kingdom has been an extraordinary partner to us. From the outside at least it looks like things have worked pretty well.

“And – you know – we obviously have a deep interest in making sure that one of the closest allies that we will ever have remains strong, robust, united and an effective partner.”

Sources in the Yes movement say Obama’s intervention had little impact on the campaign; neither was it a huge issue on its own. Rather, they claim, there were concerns about job losses which pushed some people towards a No vote and concerns about nuclear weapons which brought people to their camp.

When it came to foreign affairs and an independent Scotland, it was the prospect of being dragged out of Europe that had the biggest impact.

Frontrunner to be the next President, Hillary Clinton also intervened in the independence referendum saying, “it would be a loss for both sides”.

During his last trip to Scotland, her rival Donald Trump, said the referendum campaign was a “nasty period” and that he didn’t think Scots would want to go through it again.