Bryher Dunsby’s husband James Dunsby was one of three men who died of heat-related illness following a 16-mile exercise in the Brecon Beacons in July 2013.
Two soldiers who were safety officers during the training exercise were on Tuesday acquitted of negligence, after a judge ruled they had been given insufficient training.
“This Court Martial has revealed the shocking reality that there is still no official guidance for those conducting endurance training marches in the British Army on heat illness even five years on,” Ms Dunsby said.
“This is beyond unacceptable, and shows blatant ignorance to a vital need, where apparently 3 deaths are not enough to incite change.”
Lance Corporals Craig Roberts and Edward Maher were pronounced dead on the mountain range after suffering heatstroke during the exercise, while Corporal James Dunsby died of multiple organ failure more than two weeks later.
The judge ruled that the safety officers for the march, known only as 1A and 1B, had no case to answer.
Prosecutors alleged they had committed fundamental and basic mistakes on personal error that that led to the deaths.
But a number of inquires found systematic failures, and Judge Jeff Blackett found the men had a lack of training on risk assessment and heat illness, and that other officers in their position would not have acted differently.
“I have determined that there is no evidence of negligent performance of duty when the conduct of these defendants is measured against the reasonable serviceman of similar experience, knowledge and training,” he said.
“A board properly directed could not properly convict and I intend to stop the case now.”
Judge Blackett said the deaths, which followed a march in 28.3C temperatures in which candidates were required to carry a 27kg pack, were caused by “systemic failures within the joint forces command”.
In a statement, Ms Dunsby called upon British Army head, Mark Carleton-Smith, to “prioritise and put extra resources behind completing and implementing the new guidelines and directives for endurance marches and heat illness.”
“Ensuring the training of our forces is run efficiently and safely is non negotiable, particularly when we are asking our service personal to push themselves to the ends of their endurance,” she said.