It's a bit like airport security. It has two purposes. To make people feel a little safer while at the same time reminding them that they are at risk. It keeps the populace's attention against the middle east and in line with current military policy. It also keeps people afraid and angry enough so when the government ask for permission to bomb another area of the middle east they will approve.
However this is simply perpetuating the whole thing, which is a (now) 6 decade campaign to prevent the middle east uniting into a super power, at the same time as securing any oil they can and securing control over areas to run pipelines.
God forbid they fight back because they don't have 500lb laser guided bombs, which apparently can hit a postage stamp, so the women and children are safe.... it's a 500lb bomb, it takes the whole street out and no they are not always that accurate. If they fight back it has to be with what they have; IEDs, vans, suicide bombers.
One thing you can be 100% sure of is when that 500lb bomb lands true on the door knocker of an ISIS safe house in Syria ... taking out three buildings full of women and children next door.... on Monday morning the recruitment office queue at ISIS will be three times longer.
When they apparently deal with one bogey man, they manufacturer another, usually by ******* people off afresh bombing them.
I also disagree with the term "Terrorist". I believe it is just a faction in the middle east believing it is defending it's self and seeking retribution for the atrocities 'merka and it's side kicks in Europe have been doing in the middle east. If "terrorist" is being used because of attacks on civilians then we need to look at the number of civilian casualties in the middle east at the hands of the west. They outnumber those in the US, UK, Frane by orders of magnitude.
Remember 60 years ago, it was us who invented carpet bombing of civilians in cities. Look up how many civilians were bombed in Berlin in the 40s. We have Bomber Harris of the RAF to thank for that technique.
War IS terror.
Of course, we are were we are. So we are under threat. Putting up walls and barriers is not going to stop that. Stopping interfering and generating war and hatred in the middle east might go a lot further to stopping it though.