William joins a force for good (but not for long)

There's nothing new about royals in the forces, but them doing good works in uniform is – it's a win-win for their public image

It's the latest development in a PR initiative that befits a new generation of princes. The news last night that Prince William has been assigned to a Royal Navy frigate in the Caribbean – to join efforts disrupting drug smugglers and providing disaster aid – comes on the heels of Prince Harry's plan to visit Lesotho, with the Army, to help Aids sufferers.

That members of the Royal Family serve in the military is not news; what is worth remarking is that, in these instances, the young men are performing duties that benefit the armed forces, the disadvantaged and their own reputations. As public relations exercises go, everyone wins but the most ardent of republicans.

Prince William is due to report for duty tomorrow, ahead of a five-week attachment in the Caribbean and north Atlantic, and commanders insisted the 25-year-old will be treated like "another junior", living in cramped conditions and up for work every morning at 6.30am. He will, before travelling, be using Navy helicopters "purely for business", in an effort, no doubt, to remove images from the public's memory of the prince Chinooking into a stag party.

The Ministry of Defence states that the assignment will steel the Prince for what life can be like in conflict zones and boost morale among the service personnel he works with, but there were warnings yesterday that the lack of any front-line danger risked creating an uneven "pick and choose" culture.

In some quarters there has been criticism that Prince Harry may have used his privileged position to ask the Army to help out with three weeks of planned charity work in Lesotho, where he will follow in his mother's footsteps by helping Aids sufferers.

Prince Harry, 23, has already served in Helmand province in Afghanistan in a military assignment cloaked in secrecy, but his mercy mission to Africa aims to get maximum exposure in order to increase the profile of his Sentebale charity. He will be joined by members of the Household Cavalry's Blues and Royals for three weeks involving building care facilities for infected children.

Liberal Democrat MP Norman Baker said: "Both princes seem to have been able to choose assignments which fit in with what they want to do. While what they have chosen to do are admirable things, surely if they are going to be able to pick and choose what assignments they are involved in then it is only right that the Armed Forces should consider similar applications from everybody else?"

Conservative MP Patrick Mercer said: "Prince William will not be put in the teeth of the enemy, but this is a welcome gesture and a good attachment. It will be a good boost to the people he will be working alongside."

HMS Iron Duke, a Type 23 Frigate, will attempt to disrupt drug supply routes. However, it will be up to the prince's commanding officer whether he will be allowed to conduct armed boardings. For a future head of the Armed Forces, such experience is useful; as a way of proving that he is more than a playboy prince, it's invaluable.