You definitely don't see the big picture, do you?
I don't want to be the safest I can be in a rampage situation. I want to be safe which means not having to be in a rampage situation at all.
Where I live we don't have the right to bear guns.
...
I think you don't see the big picture either. America has been a war nation for a century, which continues to be the biggest arms exporter in the world, and continues to provide free defense capabilities for most of Europe and much of the Far East.
Without its willingness to resort to violence on behalf of others, your country and most of Europe would probably still be provinces of the Third Reich
We are grateful for the help of the US (or at least my grand parents were, I've never known this period) as you are of our own to you several generations earlier...
The past is the past, most people of these periods are long dead now and their willingness to fight with them. I'm not sure what people would have done in Europe without the US and the Soviet Union (don't forget them, they took a huge toll to split the Third Reich armies on two fronts), maybe the Third Reich would have collapsed from internal revolutions (after all the French and English people are more or less the firsts at successfully overthrowing their dictatorial states).
, and most of the Far East a part of the Japanese Empire. More recently NATO (which really means US military) interventions in places like Serbia and Libya would not have been possible without American support and propensity for solutions through superior firepower...
That kind of willingness to go to war cannot come from a relatively pacifist society like yours.
The fact that you are too big to not involve in conflicts like those doesn't mean we are "pacifists" (at least in the way you mean it). If our parents were pacifists we wouldn't have the blood of our colonies on our hands and we wouldn't continue to send troops/carriers/jets in recent wars ourselves.
American populace has always been relatively well-armed.
Europeans and other critics of American gun culture can't have their cake and eat it too;
I'm not sure I follow, are you describing the US as a hired gun for Europe and others? That is quite harsh for both the US and the rest.
The reality is more complex. I only know the recent history of my own country so I'll use it as an example. The only recent war we (the French) didn't participate in was the invasion of Iraq (don't mind the reason that's another messy subject, only that it was an exception). We were in Serbia, Koweit, Lybia for the last joint operations I remember. In the late 20th century we conducted several "interventions" in past colonies in Africa and Asia ourselves (not that I'm particularly proud of those, I'm not sure it helped the local populations or even ourselves), refused to be part of NATO for ages to remain fully independent (and our sorry clown of last president didn't forget to make the mistake of stopping this policy) and successfully developed a full-fledge nuclear weapon program. If you think France as a country is made of pacifists you are not living on the same planet we are (at least you didn't step in the craters left by our bombs). In fact this is understandable: our influence on foreign countries is obviously smaller and mostly disconnected from US interests with the obvious exception of oil-producing countries (everyone still wants to get a share in those).
they can't expect American soldiers to go conduct violence in other countries on behalf of Europe/NATO, and then return to their own home land and disarm to the point that they can't even protect themselves and their children in their home, local movie theater, at a school. It's too much of a mindset change for rational citizens and soldiers of a warrior nation to make.
I think it's a little bit exaggerated. At least there's no concrete evidence that soldiers can't disarm. I know several people who have served in the military, killed enemy combatants abroad and came home to start a civilian life. I won't swear they don't have some firearm stored somewhere but I can tell you that these guns almost never show up.