Simply not true. Annual defense spending is smaller than any of the others and the entitlement programs make up almost half of the federal budget and the number is increasing every year as the baby boomers retire. The entitlement programs represent an unfunded liability of almost $60 trillion.
So Defense is just over half of the 1/3 that is considered "discretionary". They also lump in money needed to maintain our embassys around the world as defense.