Sen. Rand Paul (R-Ky.) has never been shy about calling out government spending, and this week he trained his fire on the Pentagon. Speaking to Maria Bartiromo on Fox Business Tuesday, Paul criticized the country's $1.5 trillion defense budget, calling it "fiscally irresponsible" and arguing that America's greatest threat isn't an invasion from abroad—it's internal deterioration.

Paul took his message to X as well, writing: "I'm not comfortable with a $1.5 trillion defense budget because money doesn't grow on trees." He went further in another post, saying he doesn't distinguish between military spending and welfare spending. "Spending is spending," he said, adding that the country can't keep adding to its debt. He supports tax cuts but drew a line: "More spending disguised as a win? I'll vote no. Washington has a spending addiction, and I'm not feeding it."

This isn't Paul's first rodeo on fiscal discipline. In March, he urged the Trump administration to stop spending amid an 'insolvent' Treasury, introducing a federal budget resolution to balance on-budget outlays and revenues by cutting six cents off every projected dollar spent over the next five fiscal years. He also slammed the projected $700 billion Iran war spending amid a $2 trillion deficit, emphasizing that America's true vulnerabilities are fiscal, not military. He's criticized unchecked mandatory programs like Medicare and Social Security, which consume revenue before military add-ons are even considered.

Beyond excessive spending, Paul has argued that tackling waste, fraud, and inefficiency should be a top priority. Last month, he reacted to Treasury Secretary Scott Bessent's shocking $500 billion fraud estimate, praising the Trump administration for its efforts to combat widespread government fraud.

Paul isn't alone in his concerns. Sen. Thomas Massie (R-Ky.) also warned that President Donald Trump's policies—including the "Big Beautiful Bill," Iran war spending, and Republican spending measures—could push the 2026 budget deficit toward $2 trillion, with debt interest costs potentially exceeding federal spending.

For Paul, the math is simple: you can't spend your way to prosperity. Whether it's bombs or benefits, money doesn't grow on trees.