A bid to force 36 ex-British soldiers to appear at the Saville Inquiry was challenged at London's High Court today.
The court is being asked to block a plan to call the 36, whose names are the first on a list of ex-service personnel that could ultimately rise to 400.
The Saville Inquiry ruled in August that British troops involved in the incident must return to give evidence.
The ex-soldiers' lawyer, Mr David Lloyd Jones, told the High Court in London today that the danger to the former soldiers had fluctuated between moderate and significant.
The recent history of conflict in Northern Ireland indicates there exists a body of individuals ready to kill or maim. The British Ministry of Defence believes that if identified the claimants would be singled out for attack, he said.
"There can be no doubt as to the determination and capability of terrorists in Derry to attack and kill members of the security forces and those associated with them," he added.
The hearing is expected to last until Wednesday.