Is there any scenario in which the Arabs defeat America in the current war?

[Kontiki]

No country would give overt support to Iraq, but I could definitely see some people from other states going to Iraq pre-invasion to offer support in defense (again, not in the open, but more as "bodyguards"). I don't imagine for a second that there is much love for Saddam in the region, but I'm sure many prefer him to the US.

[JCG]

If it all comes down to a real war (ie: like WWII...):

Many, many pan-Arabs/pan-Muslims will go to Iraq as volunteers, ie: cannon fodder.

Expect more terrorist attempts in the U.S./participating countries (Britain?) either during the attack or immediately after.

Either the Republican Guard makes a "strategic retreat" (they wish) into another country via some remote region of Iraq (probably with Saddam in tow), or they stay and get killed, obviously not surrendering but giving the cannon fodder a reason to fight too.