The Romans had a saying that’s appropriate at all times, particularly when a country is being governed by a weak, can’t we all get along leftist. The saying was ‘ Si vis pacem, parabellum ‘, which means, ‘ If you would have peace, prepare for war ‘. It works every time. That’s how Ronaldus Maximus defeated the Evil Empire. It’s similar to ‘Peace through Strength’. Modern 9 millimeter pistols that are called parabellums get their name from this ancient Roman saying.
Only problem with this theory is that the Roman Republic was more or less continuously at war throughout the 700 years of its existence, leading one to logically question the credibility of Roman advice on how to live a peaceful life. :)