That's the budget. The actual outlays are less than $1 billion. Around 3-4% for the last few years.
The only way outlays are under 1 Trillion is if you ignore a great deal of defense spending. A classic trick is to hide future obligations like pensions and other benefits from current spending numbers, but if you need to hand out a pension to get people to work for you then obviously you should include either current or future spending.
So yes, you can get imaginary defense costs to ~4%, but I ask you where is the coast guard, national guard, DoE, or VA’s budget here? “The budget funds five branches of the U.S. military: the Army, Navy, Marine Corps, Air Force, and Space Force.” https://en.wikipedia.org/wiki/Military_budget_of_the_United_... Some might argue the national guard isn’t defense spending but we sent 250,000 guard members to Iraq and the guard is fielding F-35’s.
I will acknowledge some some outliers like the United States Border Patrol, while it’s job is literally defending the border it probably shouldn’t be included in defense spending.
PS: It gets even sillier, not that long ago we where hiding the cost of the Iraq war from defense spending numbers.
At best ~12% of US healthcare spending is for retail drugs, but it’s not that relevant globally when you consider how much US companies are spending on advertising vs R&D.