The return of Prince Harry yesterday from Afghanistan will have been greeted with both relief and regret. Relief that he returned unharmed, having acquitted himself well. Let us not forget he faced real risk and this could have turned out very differently. Regret that his posting was cut short by a “scoop” on an American website, instantly undermining the unusual restraint shown by the British media.

Prince Harry’s role in war maintains a long royal tradition. His uncle Andrew fought in the Falklands. The Duke of Edinburgh served in the navy throughout the second world war and the Duke of Kent, King George VI’s brother, was killed in an RAF flying boat accident in 1942. George VI himself wanted to be on board HMS Belfast during the 1944 D-day landings, as did Winston Churchill, but advisers said the potential loss of both king and prime minister would have been catastrophic.

That risk of death or capture is clearly the overriding priority when considering sending senior royals to war. It prevented Harry from being dispatched to Iraq and ensured he was brought home immediately from Afghanistan when the news broke. How much of a propaganda victory would it have been for the Taliban had he been killed in action? How much additional danger would he have put his fellow soldiers in? Worse, in an era when the enemy does not follow the Geneva conventions, imagine if the prince had been kidnapped, tortured and paraded before the cameras by machete-wielding Al-Qaeda extremists, promising and then carrying out a video beheading.

The dilemma for the top brass was to prevent this happening and yet satisfy Harry’s reasonable expectation of serving alongside his fellow soldiers. One merit of his anonymous deployment was that it did not put his comrades at any greater risk than they already faced. In the Falklands, Prince Andrew’s public role as a helicopter pilot made HMS Invincible a juicier target for the Argentine airforce. This time the Ministry of Defence secured an agreement from the media that his presence would be kept secret. The deal was always that his role would be made public once his time had been completed. Clearly, had Harry come to harm, service chiefs would have faced huge criticism for putting him at risk. The British media’s vow of silence would then have been interpreted as complicity in a mistaken decision.

As luck would have it, it didn’t happen. Harry has returned unscathed if angry; his comment about not generally liking England was baffling for a prince, but was probably aimed at the media. And the PR gamble has worked. The royal family and the army have enjoyed their best publicity for years. The young prince himself has buried, perhaps temporarily, his reputation as a spoilt toff prone to drunken spats with the paparazzi outside West End nightclubs. One less inviting consequence may be that he is more of a target now than ever. Probably better to stay away from those nightclubs for a while.

Furthermore his brief service in Afghanistan has produced memorable images of life on the front line that will be an effective recruiting tool for the army. Some will say the images give a sanitised version of the reality of the Afghan war. Others will say, quite rightly, that he has given the troops a much-needed morale boost. To have the third in line to the throne alongside you says something about the commitment of the nation’s leadership. It is a powerful symbol and message of service.

Once the fuss dies down, however, the war goes on. There was other news from Afghanistan last week. The Canadian prime minister warned that the Nato mission was “in jeopardy” unless other nations sent troops. The government in Kabul controls less than a third of the country; the Taliban’s influence is growing. That is the reality, more so than the startling images of a tousle-haired prince doing his job.