We note that Gen. Mattis doesn't like "America First" theory.
...In practice, “America first” has meant “America alone.” That has damaged the country’s ability to address problems before they reach U.S. territory and has thus compounded the danger emergent threats pose....--quoted at Breitbart
Mattis prefers the 'American troops are police' theory, employing the precinct-model of maintaining order. Kinda resembles the 'province theory' that Rome employed---before Rome collapsed. Right, General?
That's the theory under which the US equips and pays all the cops (soldiers and sailors), and takes all the casualties, too. And it's pretty damned expensive, as Rome found out. Right, General?
It's also the theory under which 9/11 happened and under which we've been taking casualties in Afghanistan for 19 years. So obviously, it worked very well. /sarc Right, General?
(By the way, "preventing the spread of Communism" through NATO and SEATO didn't prevent Communism from spreading into the US, did it, General? Remember VietNam? Yah. Smooth move.)
From about 1785 through 1914, the America First theory worked very well, indeed.