Damascus — At the border customs shed, a vivid technicolor poster of the American flag easily distracts one from the drugery of formalities such as passports and car papers.
''Old Glory'' - with the head of Israeli Prime Minister Menachem Begin appendaged to it - is being pierced by rockets.
Such posters as well as the Syrian media's coolness March 2 and 3 toward United States special envoy Philip C. Habib (on his fifth trip to Damascus), give the impression that Syria and the United States are archenemies.
Syria indirectly blames the US for the fighting in the northern city of Hama, which was said to have started in early February between Muslim fundamentalists and the Syrian Army. The government said a bomb blast at the Information Ministry last week was the work of ''Zionist and CIA agents.''
However, there are those who contend this public antagonism is just for show. And some of these are Western diplomats.
''They talk to the Americans a lot more than they let on,'' said one Western (non-American) diplomat known for his caution.
Indeed, President Reagan and Hafez Assad exchanged messages March 3 through Mr. Habib who met with the Syrian leader for two hours before flying to Jordan - an inidcation that Damascus wishes to keep its lines of communication open to Washington.
Even before this latest exchange, American diplomats admit they talk to Syrian officials above and beyond the times Ambassador Robert Pneilli is dressed down by the Foreign Ministry (most recently for the US State Department's comments on the fighting in Hama).
And it is not just in politics that one wonders whether the enmity is all it is said to be.
The US was the fifth largest exporter to Syria in 1980, behind Iraq, West Germany, Italy, and France, according to Syrian statistics (excluding armaments).
In the 1960's, Syria traded mostly with the East bloc. Now only 25 percent of its trade is with Eastern Europe (excluding armaments), diplomats said.
''They are very pro-Western in business,'' one diplomat said, noting the Syrians had bad experiences with Eastern construction and equipment.
The US often notes in its official pronouncements on the Middle East that Syria and the Soviet Union have a friendship and cooperation treaty. However,it would appear that the treaty doesn't mean much beyond arms and military training.
The Syrian Workers Party called for an economic boycott against American goods after the UN Golan vote. Information Minister Ahmed Iskander Ahmed however , told the Monitor that Syria would not boycott unless the Arab League nations did. The league did not, most likely because of its moderate Arab membership (Saudi Arabia, especially).
Shopkeepers here bemoan the dwindling number of US tourists they say have been scared off by instability in the Mideast. Easterners don't spend money like the Americans do, one shop owner readily admitted.