The issue I have with the likes of TCAS (and TAS and CADS along with all the rest) are that in times of war these will be turned off, all the lessons we learn and all the reliance we place on them in peace time will be lost in war.
The DSA Annual Assurance Report for the period April 2015 to March 2016 states the following,
"While military employment of these systems [TCAS] on fast jet aircraft was originally envisaged to mitigate risks during training and non-operational flying, recent reporting has also recognised their positive effect in current operations. In the congested multinational airspace where current operations are underway, coalition aircraft fitted with the system have been able to take action to avoid collisions on several occasions."
DV