More "relative" than you think.
Look at the wars the US fought after WWII: Korea, Vietnam, Afghanistan, Iraq, etc. The US suffered a lot less pain than any of those countries and was in a lot stronger position. But those countries were willing to face the pain, the US wasn't. That's why the US lost those wars. The same pattern goes now with Iran. You kill people on those countries, those countries hurt the American voters in their pockets.
In trade wars it might be the same mechanism. For the American people, a trade war is mostly to follow the glorious orange leader. For Canadians it is a matter of national sovereignty.
Economic growth and inflation have kept pace with gross debt for a long time, and if the US continues to stay on top of the tech industry, the raw numbers will likely continue not to matter.
Most of that was inflation, so it hurts U.S. citizens. I mean, you could reduce it even further pretty easily, but I'm not sure you would want to pay $1,000+ for a Big Mac.