What is meant by the quote, "Keep your friends close, but your enemies closer"?

Well in the game of chess you want to close off all your opponent's king's possibilities from escaping.

It's an excerpt from The Art of War by Sun Tzu. What the line means is, in warfare make allies and keep them close, maintain the politics needed to keep the friendship strong, but remain focussed the larger goal of defeating your enemy. You're friends aren't the ones trying to burn your fields or stab you in the face so it is more important that you maintain more interest in your enemies actions and affairs than your allies as it could lead to a strategic advantage

It means that your friends will always be there with you and you don't really have to watch out with them...but you always have to watch your back with enemies....meaning that you should keep and understand them closer and more than your friends. It kinda like saying that friends are on your side but enemies aren't.

I am not sure, but i hope this helps.

keep your friends close - be close with your friends, have good friends, and don't alienate them or anything

keep your enemies closer - basically it's saying [or as i interpret] if you don't want to get hurt by them, watch out so they don't surprise you or anything. if you keep them closer than friends, nothing they do will/can catch you off guard and upset you too much.

In my opinion, it is better to have them around, at least becomes less difficult to treat