Miko, I first heard this phrase, "the Russians are coming!" when I was a kid, and my Father told me about Forrestal as a historical anecdote. Later I have read several stories about this, even in the "historical" pro-Wesern books published in last 10 years.
Do you expect me to feel sorry for a defence secretary of an enemy country who signed plans of nuclear attacks against my nation?!
Made a quick search on the web - looks like it's the propaganda "hook" like Rip's "bread lines". But from what I have read in different sources - this anecdote reflects the state of anti-communist paranoia in the US in late-40s and early-50s.
Here are some links I found in Russian speaking Net:
http://www.rg.ru/bussines/econom/117.shtm(an article from official government newspaper!!! they sound like Limonov's national bolsheviks)
Another one:
http://www.smi.ru/01/04/06/145428.htmlAlmost any "This day in history" site has something like this:
22.05.1949
Джеймс Винсент ФОРРЕСТОЛ (15.2.1892 - 1949), первый министр обороны США. Выбросился из окна с криком «Русские идут!».
The anecdote looks very popular and can be called a great propaganda work, even in case it's not true.