You’d have to be counting pretty far afield things to get up to 90% but it’s easy to get to “a majority”.
About 16% of the spending is straight up defense spending and about 5% is the VA. I personally think it’s crazy to severe them and wish the va was part of the DoD. But people can disagree.
You can tell it’s nowhere near 90% because even if you counted every single non-DoD dollar as social safety net it would only be 84% of the budget.
The actual means-tested safety net (Medicaid, food assistance, SSI, housing) is only around 15% to 20% of federal spending.
As for fund deficits there are basically 4 things the federal government pays for, social security, Medicare, Medicaid and the military. Everything else is noise or interest. So when accounting for the debt load of that interest it only makes sense to assign some part of it to those 4 things.
In U.S. policy terminology, Social Security and Medicare are social insurance programs. Medicaid, SNAP, SSI, and housing assistance are means tested safety net programs.
Yes, Social Security, Medicare, Medicaid, and defense make up a majority of federal spending. But your conclusion only works by relabeling Social Security and Medicare as welfare, dismissing the rest of government as noise, and then assigning an arbitrary share of decades of accumulated interest expense to those programs.
Your last move is especially egregious. Federal debt reflects the cumulative gap between all federal spending and all federal revenue over time. You can't figure out what caused it by looking at today's largest spending categories.
Social Security's current shortfall is primarily the result of a demographic imbalance Congress has known about for decades and repeatedly declined to fully address. That makes it particularly silly to retroactively assign some arbitrary share of the rest of the federal government's accumulated debt to Social Security.
The accurate way to talk about this is that Social Security and the major health programs are a very large share of federal spending. "The social safety net is most of the budget" is a conclusion manufactured by your definitions.
Pick what labels you want to throw social security, Medicare and Medicaid into. That bucket is about 46% of federal spending and increasing fast. It’s quite easy to get to 50% without including debt payments on things that look like social safety nets (snap, aca subsidies etc).
More importantly as you point out social security, Medicare and Medicaid are growing as a percentage of the budget (and a percentage of gdp) and are not discretionary spending. Those (and defense) are the only places we have any lever to change US debt other than increasing collection. And it’s not politically viable to change them.
Social Security is kind of a "zero-sum gain," if you believe people, because we are supposedly being paid back what we spent a lifetime, having withdrawn from our wages.
[0] https://fiscaldata.treasury.gov/americas-finance-guide/feder...