Zartan, posing as The President, tortures the real President for information regarding where Cobra Commander has been imprisoned. But, as the leader of the free world (and America's highest ranking official), wouldn't the P.O.T.U.S. (in this case, Zartan disguised as the P.O.T.U.S.) be privy - and have any-time access - to this information already?
[At around 53 mins] G.I.Joe abduct the President's Chief of Staff, after Roadblock injects him, he can be seen sitting fairly normally talking. Two quick changes of shot in between conversation show him with his head back, mouth slightly open as though unconscious.
During the Zeus 1A launch, the control room shows a targeting reticule on Britain, centered over the west-midlands. The target for the Zeus weapon is London, yet the center of the target reticule is between 50-80 miles outside of London.
When Snake Eyes is taken into the prison, he's told that they descend so far that they are no longer in Germany, but are in international territory. Most conventions hold that a country's claim extends down to the center of the Earth, and up into space. (US Property Law holds the same convention with regard to a persons real property)
In the French president's suitcase are two buttons respectively labeled "avorter" and "bras". "Avorter" is French for abort, but that word is usually only used in relation to pregnancies. The correct word in that context is "annuler". "Bras" is French for arm, the body part. The correct word is "armer".
On the Israeli's weapon suitcase, the Launch button's label says "HESHIK". This is a correct word, if you are planning to launch a new perfume campaign. The correct word in Hebrew for a missile launch is "SHIGUR".
A stop sign at the prison reads "Hält" while it should just read "Stop" (even just "Halt" is rarely used on signs in Germany). The German word "hält" has different meanings, i.e. "he holds something", but it does not mean an order to stop your car.
(at around 25 mins) When the armored truck drives through the entrance of the "Einsargen" prison, the camera follows the truck and pans over the entrance bunker and fence. At the bunker there is a sign with the text: "Warnung Hochsicherheitssteckdose High Security Area". Instead of "Warnung" the word "Achtung" (meaning "Attention") is more commonly used in Germany. The word "Hochsicherheitssteckdose" (a compound which does not exist in the German language) would literally translate to "high security wall socket/power outlet". The proper German word would be "Hochsicherheitsgefängnis" which translates to "Maximum security prison".
When the G.I.Joe abduct the President's Chief of Staff, Roadblock tells him that he has been injected with amobarbital, a drug that will give him anterograde amnesia so that he wakes up "with no idea [he] ever existed". The property of amobarbital that causes people to forget events prior to the injection of the drug is actually called RETROgrade amnesia.
During the awards ceremony, Lady Jaye's hair is flowing around the top of her uniform. Military appearance standards dictate that the woman's hair is to be pulled back and up, either under the military cover (beret, cap, etc) or neatly tied up so that it is off the collar of the uniform.
The prison, set in the former East Germany, is called "Einsargen". While this, translated to English, basically means "coffin" and fits in the context, the word is a verb ("to coffin somebody") and not a proper noun.
At the prison scene, a warning sign reads in German "Baustelle! Betreten der Einfahrt verboten!" which translates to "Construction site! Do not enter the gateway/entrance!". This is complete nonsense because first the prison is not a construction site. Second, a warning sign in this environment would tell you to stay away from the premises, not just the gateway.
Soon after Roadblock, Flint, and Lady Jaye are out of the well, Roadblock is given command of the team. He shouldn't have command of the team. Roadblock is an NCO and Lady Jaye is a Lieutenant. An NCO does not out rank a Lieutenant.
They cause all the Zeus satellites to self destruct. The satellites have no bombs, no explosives, but only the "rods from gods." Destroying the satellites would cause every single "hollow platinum tube filled with a solid tungsten rod" to fall to Earth wreak havoc.
When the president of France decides to launch a nuclear attack, the footage shown on the nuclear briefcase is that of a Trident 2 launch which belongs to the American and British arsenal and not to French.