I didn't say anything about the USA joining the EU. Why is it foolish for countries like Canada, Australia, and Zealand; which have a shared culture and history with Europe. The vast majority of Canandians, Australians, and New Zealanders are of European descent.
These countries are not "officially" colonies, but they share a monarch with the UK, speak the same language as it, are part of many groups with the UK (Five Eyes, AUSCANNZUKUS, ABCA Armies, etc.) The UK and Canada now share many embassies. All of these countries share the Westminster system, they all use the metric system, they all (except for Canada) drive on the left side of the road. They all have very similar cultures, similar values, etc. Additionally, there are already three Commonwealth nations in in the EU. (The UK, Cyprus, and Malta.) why not add a few more? Also, Ireland has a similar culture to the UK, and to the Commonwealth nations; and the entry of Commonwealth nations into the EU would benefit the UK, would benefit Ireland, would benefit the Commonwealth nations, and would benefit the EU.
Think about it, would you rather the EU accept countries such as Kosovo, Bosnia, Serbia, FYROM, etc. Or would you rather the EU accept fellow "Western" and "European" countries that share the same values as Western Europeans, that share the same language as some Western Europeans, and share a similar culture to that of Western Europeans. I would much rather the EU accept Canada, Australia, and New Zealand, keep the UK, further integrate, and enlarge, and become an effective United States of Europe.
I am not the only one who dares this vision. Look on Google, and you can finds hundreds of articles, websites, threads, forums, and posts that discuss this, and many Canadians, Australians, and New Zealanders would like their countries to join the EU, and many Europeans would like the same.
If these countries joined the EU, it would get much, much richer than it currently is. It would be the world's foremost economic power, political power, and superpower. With this extra money from these countries, amazing infrastructure projects could be completed, poor, Eastern European nations could become rich, and the EU, as well as Europeans would only benefit.