DENVER -- Barack Obama's efforts to establish his national security credentials faced a potential snafu Wednesday after a few military gaffes, including one by Obama's foreign policy-touting running mate Joe Biden, were made Wednesday during the third night of the Democratic National Convention.

Biden, who was chosen by Obama as his vice president in part for his foreign policy resume, stumbled during his acceptance speech when he said that Obama suggested a year ago to send two more battalions to Afghanistan.

Biden meant to say brigades, which at 4,500 troops, are three times the size of battalions.

The slip was sure to be caught by Democratic opponents and the Republican National Committee responded with glee, zeroing out its Biden gaffe clock, which it created in the hours after Biden was chosen as Obama's running mate.

According to the clock, Biden's gaffe came four days, 17 hours and 59 minutes after his last one, when he called Obama, "Barack America," during their debut appearance in Springfield, Ill.

"Does the Republican Party really want to debate who is better versed in foreign policy and national security," Obama campaign spokesman David Wade told FOXNews.com via e-mail. "If we wanted to stoop to the level of the McCain campaign, we'd point out that John McCain can't get straight the difference between Sunni and Shiia and seems to think Czechoslovakia is still a country."

Even so, other gaffes on Wednesday could dissuade military voters that Democrats hope to attract.

Among the speakers Wednesday night was Sgt. Major Michele Jones, who the Obama team touted as the first woman to hold that position in the U.S. Army. But no woman has ever reached that level. Jones was in the Army Reserve.

In Steven Spielberg's video tribute to wounded veterans,  one vet who got out of the military in 1997 said, "Some are serving 18 months, coming home and turning around and doing another 18 months."

But aside from Gen. David Petraeus and his spokesman, no forces have served 18-month tours. The administration had expanded tours to 15 months, but they have now been reduced back to 12 months.

FOX News' Jennifer Griffin contributed to this report.