My time has come.
1. Be the US of A. This has multiple advantages, the first being that all other countries are vassal states in all but name, and the second being that no outside force could ever even come close to defeating the US, and I will die on that hill.
2. Threaten to leave NATO and stop giving any foreign aid to Europe, while also actively developing natural resources in the US. Without the inherent protections the US gives Europe, as well as the military and intelligence support Russia will quickly overrun eastern Europe. Use this leverage to gain almost complete control over NATO member states.
3. Seize the Suez Canal, taking control of around ten percent of global trade, this can be most easily accompished by using staging grounds in Israel, and while we're at it lets take out all the oil refineries hostile countries, sending the entire region into chaos and cutting off oil supplies to all enemies except Russia.
4. Take control of Canada and Mexico, and keep going south to Panama, where we seize the Panama canal as well. This would be incredibly easy as we basically control the territory already.
5. Using bases in Japan, Korea, Guam, and corroboration from Taiwan and Vietnam, cut off all overseas trade to China. Within a short amount of time the lack of food and increasingly impossible conditions the CCP will collapse effectively overnight. Their ballistic missile stockpile will pose a small problem, but if they become too much of an inconvenience, and you don't mind warcrimes(which why would we who can punish us?) We bomb the Three Gorges Dam, cutting off power and causing massive flooding across the majority of the country, killing the already strained power grid, flood response, and infrastructure.
This also serves the double purpose of cutting of Russia's last major trading partner and allowing us to completely surround North Korea.
From here it's just wrap up, and rebuilding multiple completely destroyed countries.
TLDR: If you aren't the US the only reason you exist is because we allow you to.