The SNP has compared its fight for Scottish independence with the American Revolution that went on to create "one of the most powerful nations in the world".
The party hit back at an editorial by the Washington Post newspaper which claimed an independent Scotland would be "unable to contribute meaningfully to global security" and lead to "a less stable world".
In a letter to the Post's editor, a US aide to SNP Westminster leader and defence spokesman Angus Robertson said "people in London would have read similar warnings about a small upstart country just across the Atlantic" during the war of independence with Britain 230 years ago.
Christopher Mullins-Silverstein, a Chicago-born adviser to the Moray MP, wrote: "As with Scotland today, that country was resource-rich and filled with potential but was held back by a distant government in London. Somehow, that small country overcame the odds to become one of the most powerful nations in the world."
The editorial "missed the mark" and contained "troubling assertions" about European democracy which "run afoul of core American beliefs", he wrote. "I doubt that any American would want to see his or her representation decreased or independence denied. Why should others be denied what we treat as an inalienable right?"
Mr Robertson spearheaded the SNP's controversial new support for Nato, which split the party and led to the resignation of two MSPs. SNP opponents of Nato believe joining the nuclear-armed military alliance would leave Scotland beholden to the interests of the US and its closest allies in London.
"The two capital cities which would be keenest to keep Scotland in Nato are Washington and London," the party's anti-nuclear branch said. "In both cases this is because they want to retain nuclear weapons on the Clyde."
Justice Secretary Kenny MacAskill, who provoked a US backlash with his decision to release Lockerbie bomber Abdelbaset al-Megrahi, was widely credited with swinging the pro-Nato vote by declaring he is "no US lapdog".
Meanwhile, one of the Post's major rivals, The New York Times, has added another voice to the debate about Scotland's uncertain future in the European Union. Political scientist Robert Young, author of The Breakup Of Czechoslovakia and The Secession Of Quebec And The Future Of Canada, said seceding states "do not automatically enjoy treaty rights".
The Scottish Government says it believes Scotland would inherit the UK's existing treaties and be automatically accepted into the EU. It has no specific legal evidence to back this up and has not approached Westminster to ask the European Commission for clarification.