FUBAR: (adjective) Ruined, messed up, in a state of complete and utter disarray. Originally US military slang (World War II vintage), abbreviated from Fouled Up Beyond All Recognition*
Variant forms: fubar (no caps), foobar, foo-bar
Clever communication has been an important part of waging war for a very long time. Codes and jargon help soldiers interact efficiently, and with the increasing complexity throughout the 20th century, that has meant a profusion of acronyms and abbreviations—some of them useful even to us civilians.
From the PFC on KP duty (or maybe going AWOL), to the NCO taking some R & R, or going to the PX—even the CO uses abbreviations, it is just SOP. Whether they are going through BT with a heartless DI or sitting down to eat a MRE, all the GIs (even WACS, SEALs, flyboys, and leathernecks) find shorter and more efficient ways of saying things.
Unsatisfied with the official abbreviations, they invented their own crop—most of them quite colourful. In addition to FUBAR, World War II brought us SNAFU, a word meaning "Situation Normal, All Fouled Up"* and CATFU which means "Completely and Totally Fouled Up."*. Later generations of grunts, humping the boonies in the Nam gave us REMF, an insulting term for a "Rear Echelon" officer who doesn't have to see the fighting.
FUBAR (and SNAFU too) entered the vocabulary of civilians, it is a perfect, funny way to say that things are amiss. As more people used the word, alternate meanings for this little term began to emerge. Most variations start with "Fouled* Up Beyond All ..." the next word can be reality, reason, recall, redemption, recovery or repair. Additionally, the A can stand for Any. A couple of additional versions are "...But All Right" or "...But Always Running." A particularly apt one is "Fouled Up By Army Regulation."**
A couple of alternate explanations for the origin of FUBAR have come to light, as well. Some people believe that the word had pre-WWII origins in the German term furchtbar, which means 'dreadful' or 'awful.' Others contend that the word foo had come into popular usage in the 1930s as a sort of disgusted interjection (this is likely true, and it is probably a sort of sound effect word, like 'pshaw' or 'phooey'—whether it had much to do with FUBAR or not is another question). In that case, where the '-bar' came from in that latter case remains unexplained.
One final etymological theory of special magnificence remains to be examined. A few historians feel that there is a connection between FUBAR and the Norse Runic alphabet. The system of runes was called the futhark and some clever individuals draw a connection between this word and the WWII-era term. Because, you know, when things get messed up, GI's are likely to invoke the names of ancient alphabets—like they do.
* We all know that the F can stand for stronger words than 'fouled.' don't we?
** Running gag
BrevityQuest 2006
References:
http://en.wikipedia.org/wiki/Foobar
http://www.answers.com/topic/snafu
www.urbandictionary.com (although they weren't very helpful)