The threat the North Vietnamese posed to America was minimal. The threat Islamic terrorism poses is maximal. It is even greater than that posed by the Japanese in their attack on Pearl Harbor. The American people understand the scope of this threat, the liberals, and apparently Mr. Podhoretz, don't.
Being a so-called "conservative" Norman Podhoretz must be even denser than Tom Daschle. But of course he's not is he? So what's the purpose of his article?
First, the threat posed to America by international communism was immense. Second, Podhoretz is simply making the point that the Vietnamese War was a popular intervention which was nonetheless undone by a tiny but determined and critically situated minority. He is simply warning us that if it happened then it could happen again. Indeed as he points out, there are already signs that the anti-America crowd aren't even waiting for a decent interval to begin their effort to undermine our resolve.
Many already seem more concerned about offending Muslims than defending ourselves notwithstanding that this attack occurred in America. His analogies are on target.