The key but under-acknowledged role of foreign military advisors in U.S. history

On the train from Exeter to London the other day I was
re-reading retired Lt. Gen. Dave Richard Palmer's
Summons
of the Trumpet, partly because I decided I didn't really get it the
first time around when I read it a couple of years ago. I also picked it up
again because it as close as I think anyone has come to writing an operational
history of the Vietnam War.

The book is good, but a bit dated in places. I think General Palmer
is over-optimistic about the implications of the Ia Drang fight. He also seems
credulous about the Gulf of Tonkin incident, especially in his interpretation
that Hanoi was foolish to launch such an attack.

That said, overall I think it is the best book I've been
able to find for an overview of what actually happened in the war, rather than
what people were saying about it.  

This is what Palmer writes about the important role foreign
military advisors played in the creation of these United States of America (pp.
27-28). They might be appreciated by anyone trying to advise Afghan forces
nowadays:

"There was once a time when the American army needed foreign
advisors. . . Having neither a nucleus
of professionals nor a backstop of military tradition to draw on, Congress
turned with scant hope to Europe for trained officers. They came. Lafayette,
Steuben, Kosciusko, Dekalb, Pulaski, Duportail -- just to mention a few of the
better known names is to evoke an image of the vitally important role they
played in the winning of our War of Independence.

These advisors tackled an awesome task: molding an army from
raw material in a backward country in the midst of war. A strange and often
inhospitable environment seriously complicated their job, not to mention
problems created by the barriers of language and other cultural differences.
Then, too, buffeted by puzzling and sometimes petty crosscurrents of political
and personal jealousies, . . . the foreigners often suffered acute frustration
and actual bitterness. Nonetheless, they persevered.

. . .  Another unchanging reality of advising is the more
or less constant cocoon of frustration enveloping the advisor. Adjusting to
advising is a greater individual challenge than can be easily imagined by
anyone who has not done it.