//Who exactly is sanctioning these deals? I as a tax payer certainly did not and we, the people of this country did not. //
as a taxpayer, it would be impractical if you (and me, and everyone else) had to be consulted on every aspect of UK policy - I mean, look how much controversy has been created by just one such vote last year.
in the main, we elect a member of parliament to represent our interests. if you want to do all you can to ensure that your MP doesn't sanction dodgy arms deals, you need to question all of the candidates as to whether they really do represent your views. willing to be that very few voters actually bother; you may not have sanctioned the deals, but if you didn't try and elect the right MP, you could be said to have caused it to happen.