We have a Trump Doctrine. It's principled realism and here are the 4 principles: Protect the Homeland, Promote American Prosperity, Peace Through Strength and Advance American Influence Abroad. Read the National Security Strategy
Power is central. American economic power is at the foundation and it’s the engine of military power. Is it true realism? Yes and no. Realism in International Relations theory prioritizes power, and the balance of power, over and above moral and cultural preferences of any individual state.
Sovereign states observe rules of the road and engage in peaceful competition over trade and territory. 20th Century realism was was a counterweight to Soviet world communist expansion. Realism was also a warning not to reach too far with the Wilsonian spread of democracy. No isolation, but no nation-building or pre-emptive wars, either. In his May 2017 Saudi Arabia speech, Trump made clear he’s not there to tell other countries how to live or worship. That’s classic realism. So is “We will get along with all nations willing to get along with us,” again from his campaign speech.
Trump buys that but adds more. Old-school realism barred a statesman from applying domestic principles to international conduct if they might rock the boat. Of course, Trump is going to rock the boat. For Trump realism includes defending borders: “a nation without borders is not a nation.” Hard to disagree with that one.
Trump’s principled realism – no doubt a speechwriter phrase, perhaps from the erudite Dr. Nadia Schadlow – adds a twist. Values come back. Trump wants to keep American principles up front including broad religious tolerance and per his campaign speeches, LGBTQ rights.
Advancing American principles spreads peace and prosperity around the globe, says the conclusion of the National Security Strategy. He's been consistent. Trump in Saudi Arabia said: “This is a battle between barbaric criminals who seek to obliterate human life, and decent people of all religions who seek to protect it.” He invited Persian Gulf and all Muslim-majority states to acknowledge selected common principles – boys and girls growing up peacefully, ancient cultures, modern achievements, opposing barbaric criminals – and band together.
The National Security Strategy tells us Americans to stand up for ourselves. Love of liberty is intertwined in "every ligament of our hearts" as George Washington put it. Principled realism, American style.