So it's okay that the US military is used as the world police?
Neither the war in Afghanistan nor Iraq were justified. Not to mention Saddam was an ally of the US for some time. US even gave Iraq the chemical precursors for their chemical weapons program.
Yes, what's happening in Ukraine is awful, but by this logic, why has the US been supporting the Saudi Arabian regime in its war on Yemen? Why isn't the US providing humanitarian aid to the people of Yemen? There's political motives for nearly every recent conflict the US has gotten involved in. It's not for moral reasons. The "moral reasons" politicians give are sales pitches to gain support.
We've got our own problems at home. The taxpayer money thrown away on contractors and needlessly getting involved in these conflicts could have very well gone towards funding universal healthcare and higher education programs for the public, rather than giving folks the stick and carrot of putting their life on the line for such "benefits".
They're "benefits" because they're walled off in our country, whereas elsewhere they're covered by taxes. Providing them to each citizen from day 0 would only boost productivity/GDP in the long run, if money is the concern. But it's likely there's an awareness of that, and a worry of a healthy and educated population getting ahead, which would disincentivize people from joining the military.
A government that doesn't provide its people with, at the very least, healthcare, and uses healthcare (and education) as a means of drawing in folks to put their lives on the line in its military for selfish and offensive purposes, does not give two shits about its people. Its interests are morally devoid and elsewhere, not with its people nor the people of other nations.