You don't go to war with your major trading partners, it would be economic suicide. Of course, the EU isn't the only reason why there hasn't been (more) war, but it's a significant contributing factor along with organisations like NATO.
>From regulations on fruit
Ugh. I wish people would stop bringing this horrendous straw-man up. Those regulations replaced a dozen separate national regulations with one single European regulation. That's good for trade and good for consumers. It's not something to bitch about.
>Thankfully the UK will not be part of the EU for too much longer.
You may be waiting a lot longer than you think.