Why Are We Celebrating Armed Forces?

This Saturday is Armed Forces Day and David Cameron is urging us all to show our support to 'those which help protect our values and keep us safe'.    
Of course after a succession of unpopular and pointless wars, the military has had to undergo a bit of a public relations initiative and the message seems to be the army, navy and air-force are doing all they do all over 'to keep us safe'.
My question would be who exactly are they keeping us safe from?
Certainly Saddam Hussein in Iraq wasn't a danger to us, neither was the Taliban in Afghanistan and we were best buddies with Colonel Gadaffi in Libya just before we decided we didn't actually like him much and helped remove him but in no way, shape or form was he a danger to our safety.
The last three wars were not fought to keep us safe then and the danger now seems to be ISIS but we are not at war with them as they violently and with murderous intent step into the vacuum we created by removing the aforementioned leaders.
Russia seem to be the latest big bad but their are not lines of Russian Tanks lining up ready to roll across Europe and stop only once they reach this side of the Channel.
So again, who are the military keeping us safe from exactly because from where i have been sitting for the past decade it seems that our military have been used less for defending us and more for attacking countries whose leaders we don't like and in the majority of cases, happen to be soaked in oil so why would we want to support that?
How about a day where we support those people who save or improve lives instead of  those who destroy and take them.
A Nurses Day i could support but celebrating our military who the politicians have used to bring mayhem to large swathes of the globe? Nah, i will take a pass thanks.