A few years ago, during a heat wave in North-Eastern US, the electricity demand in an area overcame the grid's capacity, causing a cascading disaster of low tension and surges spreading over several states, causing a total, extremely long blackout.

Found it. https://en.wikipedia.org/wiki/Northeast_blackout_of_2003

It lasted anywhere from 6+ hours to nearly FOUR FUCKING DAYS. It was in 2003

That shit was rolling on its merry way totally out of control untill it met Québec's border, at which point it was instantly stopped by our grid being separate and having security mesures.

Globalization means when something fails, the whole place fails together.

Nations should strive for self-sufficiency and maintaining their culture.

Borrowings, trades and some influences? Sure, to an extent. Open borders and globalisation? Fuck no. The world needs different nations to keep existing and compete to develop their own unique things for some of those things to eventually benefit other nations and further nations and humans in general.