11% of America's GDP and 9% of all jobs rely on the export of services and goods. Autarchy is impossible in this day and age, unless you content yourself with North Korean living standards. And that's why Ukraine, Taiwan or any other major world crisis does matter for America's future. Isolationist fantasies won't change that.
People like Lindsey Graham aren't warmongers, nor do they advocate aiding Ukraine out of the goodness of their heart. He's just smarter than Laura Loomer, Tucker Carlson or all the other propagandists who confuse emotions with facts.