Two anti-war campaigners who broke into an RAF base in Gloucestershire said they were acting to stop a war crime.
RAF Fairford housed B52s in the run up to the Iraq war
Dr Margaret Jones, 57, of Bristol, and Paul Milling, 61, of Ambleside, Cumbria, pleaded not guilty to conspiracy to cause criminal damage.
The prosecution told Bristol Crown Court that the pair broke into RAF Fairford in March 2003 and were caught with bolt and wire cutters.
Before they were arrested, they had damaged fuel tankers and tractor units.
The jury were shown a video of the damage they caused, and Peter Blair QC said that they admitted causing the damage.
"They took the law into their own hands. They were fully aware that their actions could be seen as unreasonable by a jury," he added.
The defence will claim that the actions of the two were lawful because they were attempting to prevent a war crime.