The inviolability of America's $30 trillion debt pile is foundational for global markets and the US economy. In this essay, we identify a critical loophole: the President's underappreciated power to dramatically change its legal structure. In light of President Trump's mooted "Mar-A-Lago Accords," Congress should constrain that authority to prevent a potential catastrophe. We begin by detailing-for the first time in the literature-the arcane legal structure underpinning America's sovereign borrowings. We find that while the President lacks authority to retroactively change the terms of outstanding debt, they can accomplish similar goals by issuing new debt instruments granting themselves unprecedented powers. Within a year, a determined President could reconstitute 80% of the national debt to their liking, in the process usurping Congressional power over the purse. To safeguard the separation of powers and prevent any President from unilaterally engineering a global debt crisis, Congress should act.