An interesting article from earlier this year that appeared in The American Interest. If you're not a subscriber (which I am not), this will be the only piece you can read from the site this month.
I think there's a general failure to understand the need for security arrangements like NATO or the one the US has with Japan. This need has been demonstrated by history.
Russia's ability to wreak havoc and the need for intergovernmental cooperation in combating things like terrorism are compelling reasons for keeping NATO, for example.
The USA's decision to keep Japan demilitarized and under the American nuclear umbrella has, for decades, prevented a nuclear arms race between China and Japan, also, proponents would say, something that would be contrary to US interests.
What, some will wonder, about George Washington's warning, given in his farewell address, against "entangling alliances."
Washington's words have often been used by people like the "America Firsters" who, after the rise of Hitler, effectively prevented the US from working with other western democracies to, at first, thwart and then, to defeat, the Nazis. Millions of lives were lost as a result of the drag they inflicted on American policies.
Washington was, in fact, the father not only of his country, but also of US foreign policy realism. His warning against "entangling alliances" was rooted in his historical context and was advanced in service to the guiding light of his approach to foreign affairs: to always do what was in the best interests of the country.
At that time, that meant keeping the fledgling United States from becoming a partisan in the conflict between the western world's superpowers of the time, England and France. To be associated closely with either one, to be allied with one country or the other, would put the development of the then-delicate United States at risk. Washington wanted to give the US breathing room to develop its political and economic life, to be able to engage in trade with both of the two major powers without picking sides. When you're the littlest and weakest kid on the block, it's best not to rile up the two neighborhood bullies.
Had Washington been around at the end of World War 2, when the US emerged as the preeminent power of the world, at that time hurtling into a Cold War with a third world economy that had atomic weapons (the Soviet Union), I'm sure that his counsel would still have been to do what was in the best interests of America. At that time, that would entail recognizing the country's changed status among nations and understanding the need to provide leadership to alliances that preserved the freedom and stability for the US. NATO was one of the post-war institutions that did that.
Many argue today that NATO has outlived its usefulness. As indicated above, some disagree with that. They also would say that mutual security arrangements are beneficial to US security and allows this country to act as the "senior partner" in security arrangements with other countries.
It seems to me that the Achilles heel of these arrangements, alluded to in the linked piece, is the failure of nations under the US security umbrella to pay their fair share in manpower, arms, and money. As the article also says, this has allowed western European partner nations to develop social insurance policies that the US doesn't feel it can afford, in part because of other outlays, including those for NATO.
History demonstrates that a United States turned in on itself is less secure than one engaged with the world.
How that might be expressed today is a political issue and I don't advance political opinions here, just historical observations.
But my observation is that addressing how to renew partnerships like NATO in light of cyber-terrorism, terrorism, and the aggression of nations like Russia and China is probably something that should occupy the time and thinking of the next president and the American people.