Its mentality has been like that for quite a while.
Seems a bit closer these days, but not that long ago the mood was generally (and within the government) sort of like europe?LALALALALALAeuropeWHAT.I.CAN'T.HEAR.YOUlalalalala.
The history bit is highly debatable, there is at the very least the Roman Empire to mention before that. Though it's still the last of the great powers... not counting Germany in this one, they did set themselves up for some bad feedback.
I'm not sure how much the island factor has contributed. It's not really something like Japan where nobody conquered it much, meddled in it and where things were pretty isolated both ways for a long time.







