In a free market system all trade is voluntary. Every other economic system relies on force of some kind. In command style economies political power is used to extract resources from one and give to another.
Where entire nations are concerned, a country can use free market principles within its own borders but use economics by force where trade with other countries is concerned. Free markets between nations amount to free trade. By free trade, I mean no restrictions at all on on goods and services entering and leaving the country. Any other system of managing trade results in small wars breaking out eventually a large war. The United States makes trade agreements that are claimed to promote free trade, but they are actually always something else.
So, does the United States want peace or war? It doesn’t matter what the preferences, is since belief in free market ideology is waning, there will war and plenty of it. There are at least two best practices that must be followed by any country which claims to be an agent of peace.
Foreign policy must be based on principles of morality. All but a few wars are war for profit.
Free trade must be initiated unilaterally. In the U.S. there should be no restrictions on foreign good leaving and entering the country, provided they are legal. Where free trade is concerned there are winners and loser but net prosperity is always at an optimum and the possibility of war is always at a minimum.
Basically, if the United States genuinely wants peace, the best thing to do is move back to the free market ideology. National defense begins by using the economic system that is the only source of peace mankind has ever known