Ok, so here's the thing, if nothing happens that'd require the SAMs to launched, then nothing will happen if they're deployed. The British army is unarguably one of the best (if not the best) trained and disciplined, the chances of one of these missiles being launched accidentally or erroneously is practically non-existent.
The only rational argument I've heard against them being deployed is the danger of shrapnel if they actually hit something. And, yes, this is a valid concern. However, if any kind of hostile aircraft is in range of these missiles, then not shooting it down is guaranteed to cost a huge number of people their lives.
This is simple damage control, weighing the cost in lives of a handful of people who'd be in the wrong place at the wrong time, to the millions of people who'd undoubtedly be the target of such an attack.
The only rational argument I've heard against them being deployed is the danger of shrapnel if they actually hit something. And, yes, this is a valid concern. However, if any kind of hostile aircraft is in range of these missiles, then not shooting it down is guaranteed to cost a huge number of people their lives.
This is simple damage control, weighing the cost in lives of a handful of people who'd be in the wrong place at the wrong time, to the millions of people who'd undoubtedly be the target of such an attack.