Will a war in the Middle East (United States against Iraq) affect
restaurant sales in Manhattan? The restaurants that I have in mind are
expensive, upscale, French Restaurants with 3 or more stars.

A rule of thumb with expensive New York restaurants, is the more
tourists that come to the city, the more customers and the better
they do. Although New Yorkers do occasionally dine at fancy New York
restaurants, the largest percentage of their customers are visitors
from out-of-town.

Although each situation is unique, it is probably safe to say that 
restaurants in New York, especially the more expensive ones which
rely on out-of-town visitors, will be effected. The reason is similar
to the after-effects of September 11th, when the city's businesses, particularly
those that relied on tourism, were severely affected and the city
government had to put into effect special programs to encourage people
to eat out again.

Unlike the last war with Iraq, in this war there are threats on US
soil and NY has been singled out. This alone will make people hesitant
to come to New York, as well as fear of flying unnecessarily. 

So, it will not be so much the war in Iraq that will impact NY restaurants,
but rather the US terror threats associated with it.


Description of New York's 'Dine Together' program:

http://www.popsustainability.org/news/pr012002.html

Report of the effect of 9/11 on New York businesses including restaurants:

http://www.aafny.org/research/dl/911study/04ChapterTwo.pdf

Well, I hear French products, and possibly restaurants, are already
being affected because certain people are taking a dislike to the
French govt's stance on ware with Iraq.  But I don't suppose that will
apply to upscale joints as much.

No.

Darn laptop touchpad. I didn't even get started. I mean't to say I
don't think that their will be a dramatic effect. I think their might
be a slight decrease in profits. But that could be normal. Most
restaurants have their hard times. Yet, don't we all?