The Washington Post, which exposed the Watergate scandal that forced the resignation of President Richard Nixon, claimed in a lengthy editorial that Scotland would be "unable to contribute meaningfully to global security" and significantly weaken the UK, which it regards as the US's foremost ally.
Independence could also destabilise the pound and cost the UK its seat on the United Nations Security Council, the paper fears.
The SNP has complained to the newspaper and pro-UK parties said the editorial underlined the need for clarity on Scottish Government plans.
The Post claims Alex Salmond's "would-be country" would withdraw from Nato and expel British nuclear submarines from its waters.
It poses the question: "Does it make sense for Scotland to become an independent nation, ending 300 years of union with England and Wales?
"And would it make any difference to Americans? The answer to the second question is an unfortunate yes: An independent Scotland would significantly weaken the foremost military and diplomatic ally of the United States, while creating another European mini-state unable to contribute meaningfully to global security."
The papers says Scottish independence is part of a "worrying trend" towards European regional fragmentation, citing separatist movements such as Catalonia in Spain and Flanders in Belgium.
"Like small US states, European statelets could command disproportionate representation in EU bodies; today's provincial politicians imagine themselves seated alongside Germany and France at European summits," it says.
"To be sure, a more local government can be more efficient, more democratic and more attuned to citizens' interests. But the more fragmented Europe becomes, the less it will be able to use its collective strength on the global stage, both in military and diplomatic terms.
"Though a weak EU diplomatic corps exists, a bona fide continental military is a distant dream, at best. A weaker Europe means a less stable world, and less leverage for the democracies."
Labour's shadow Scotland Office minister, William Bain, said: "If the contradictions and gaps in Alex Salmond's foreign and defence policy are being discussed as far afield as Washington, then some clarity is long overdue and the people of Scotland deserve to know the answers to basic questions such as how we would have more influence as a separate state than we have as part of the UK."
Jackson Carlaw, deputy leader of the Scottish Conservatives, said: "Alex Salmond is very keen in quoting Burns when he says: 'To see ourselves as others see us'. Well here is a fairly definite and concise view of how others see a separate Scotland's role in the world."
An SNP spokesman said: "This is an editorial in a newspaper, and the SNP have already been in touch with the paper to point out that it contains factual errors. On defence, for example, the SNP's conference passed a policy for an independent Scotland to be a non-nuclear member of Nato, similar to Norway and the vast majority of Nato members which do not possess nuclear weapons."