Since the end of the Cold War, the strength of the armed forces has been cut by almost a third, from 305,000 to 210,000 people. Environmental campaigners are now questioning whether the Ministry of Defence still needs to occupy 238,500 hectares of land, some of it in Britain's most beautiful countryside.
The decision by the MOD to hold a meeting later this month to consult on a national strategy for its rural estate, has been welcomed by campaigners.
"We have pressed for meetings before," said Vicki Elcoate, director of the Council for National Parks. "But there has never been any public consultation on what other options there might be. If they do really need so much land, they could use low grade agricultural land rather than national parks."
The national parks, including those in the Lake District, the Peak District, the North Yorkshire Moors, the Yorkshire Dales and Pembrokeshire, were set up after the Second World War to provide areas of peace away from urban sprawl. Access to and conservation of Ministry of Defence land in them and other areas, such as the Dorset coast and Salisbury Plain, have been matters of concern to walkers, residents and environmentalists for years.
"I agree that they need to train to use weapons," Ms Elcoate said. "But I don't think they should be training in national parks. We say they have not looked at the alternatives such as using more simulation, getting new training areas, training overseas, training more effectively - they book a training slot and then don't use it but no one else has access.
"We have recently discovered that the RAF deliberately fly over these areas because they say there are fewer people to disturb," said Ms Elcoate. "But these low-flying aircraft are very disruptive for residents and walkers. People go there to get away from noise and disturbance. The quality of the land and the loss of it are both issues which concern us."
The Ministry of Defence argues that the lack of public access to the land helps to conserve it. But it says it has improved public access anyway, and is taking steps to reduce the impact on the environment from its own activities, consulting site by site with local conservation groups.
"There will be a change," said MOD press officer Kate O'Connor. "We have to look at how we use the estate and we have to be as efficient as we can. But it will not mean a release of land. This is the first time we have looked at where we go from here nationally."
The reappraisal of the estate was prompted by changes in the armed forces following the Strategic Defence Review last July. Perversely, while the overall number of personnel has fallen, the move to Britain of 2,500 troops formerly trained in Germany could put more pressure on open land.
Kate Ashbrook, chairwoman of the Ramblers' Association access committee, said the association - currently fighting for a legal right to roam on open land - has been pushing for years to get better access to areas such as Dartmoor, the Pembrokeshire coast and parts of the Lake District used by the Ministry of Defence.
"It occupies some of the best open land in the country," she said. "We have been pressing for the land to be released but you just come up against the same answer: `we have to train there'."Reuse content