Around 200 activists gathered in Cardiff last Saturday to protest against the development of a £14 billion military base in South Wales.
The St Athan Defence Training Academy would provide training and assistance to British forces and allies around the world.
Protesters were banned from marching through Cardiff city centre as police used the Public Order Act, and forced the demonstration away from the main shopping centres in an attempt to minimise its impact.
The academy would be run by the private Metrix consortium which includes Raytheon, a manufacturer of arms and cluster bombs.
'You could tell that today's demo was a success because it had so many new people there,' said Jonny Jones from Cardiff Stop the War Coalition.
'It's taken a while for this campaign to really find its feet but the presence of a large number of university and school students shows that we've made a real breakthrough.'