As a definitive end continues to elude fighters in Libya's civil war, Britain is going to try to tip the scales by sending in military advisors to help the rebel forces. U.K. Foreign Secretary William Hague announced today that the team of military officers would join a group of British delegates already working with rebel leaders in Benghazi.

The officers are not to participate in combat or even direct training or arming of rebel soldiers, Hague stressed to Al Jazeera. Instead, "they will advise the National Transitional Council on how to improve their military organisational structures, communications and logistics, including how best to distribute humanitarian aid and deliver medical assistance."

But that promise is sure to sit uneasily with those who remember the Vietnam War, where the United States initially got involved in that conflict by sending military advisors. Just hours after the announcement of the British advisory troops, chatter is turning toward the possibility of so-called mission creep in Libya.

At Britain's Channel 4 News, correspondent Alex Thompson took to the blog to ask, "where does it end?"

[J]ust a short time after the Prime Minister was insisting that resolution did not and would not, mean boots on the ground – boots on the ground in the form of British military advisors is precisely what has been announced.

So we move from air attacks … to providing flak jackets and mobile phones … to supplying communications equipment … to soldiers on the ground acting as advisors to the rebels about whom we still know very little. Mission creep? Some conclude that it is. Foreign Office and UN lawyers will say it is not because of that catch-all phrase “all means necessary.”

At Spectator's Coffee House blog, David Blackburn gave voice to Hague's fervent denial that the advisors constituted a military force. The phrase "Boots on the ground" is obviously about to be beaten within an inch of its life once more.

Hague’s statement suggests that if British troops were to train rebels, that would constitute ‘boots on the ground’. As training and mentoring, of the sort that has been used in Pakistan and Afghanistan, is apparently off limits, it’s hard to see how far the allies can help the rebels.

The similarity to Vietnam is lost on no one. Still, Liberal Democrat MP Sir Menzies Campbell told the Guardian's Andrew Sparrow, "it must not be seen as a first installment of further military deployment. Vietnam began with an American president sending military advisors. We must proceed with caution." Sparrow then tweeted that to remind us of its poignancy.

Whatever you think of the mission of the advisors, the linguistic reminder of Vietnam is unavoidable. Maybe folks are hoping that if it stays very clear that the UK soldiers are treading in dangerous, history-repeating territory, further mission creep will face larger challenges? Either way, it's interesting that what may have been a euphemism for combat troops 40 years ago is now one of the biggest red flags in the parlance.