That's because in the United States, it's politically easier to spend $1 trillion on war than $1 Billion on infrastructure.
If you propose any program that broadly benefits the American public, concerns arise about "fairness": either that the money is being spent at all, or that it may benefit those undeserving -- either because it will benefit the slovenly or because it will benefit "the rich"[1]
[1] An aside: When talking about social programs in America, "rich" usually starts at 1.5x the median household income. But for taxes, you get long drawn-out arguments as to why a household making $500,000 a year is still middle class because they can't afford to quit their job and retire.
If you propose any program that broadly benefits the American public, concerns arise about "fairness": either that the money is being spent at all, or that it may benefit those undeserving -- either because it will benefit the slovenly or because it will benefit "the rich"[1]
[1] An aside: When talking about social programs in America, "rich" usually starts at 1.5x the median household income. But for taxes, you get long drawn-out arguments as to why a household making $500,000 a year is still middle class because they can't afford to quit their job and retire.