It's an American imperial ambition. If you want some details there's a lot of information online about it.
It's historic but Trump is keen to implement it and directly quotes it on numerous occasions.
We are in trouble, big trouble and while people keep cheering on America we are in grave danger. Cuba, Canada, Venezuela, Greenland are now targets. Britain is already being attacked by the USA, basically through media and economic sanctions....
We need to rejoin the EU and the head of NATO needs to be replaced. We need a NATO that doesn't include America....it's influence on our defence is now our biggest threat.