It reads like a dry, 1,184-word memorandum about fiscal projections. But the International Monetary Fund’s memo on Greek debt sustainability, explaining why the I.M.F. cannot participate in a new bailout program unless other European countries agree to huge debt relief for Greece, has provided the “Emperor Has No Clothes” moment of the Greek crisis, one that may finally force eurozone members to either move closer to fiscal union or break up.

The I.M.F. memo amounts to an admission that the eurozone cannot work in its current form. It lays out three options for achieving Greek debt sustainability, all of which are tantamount to a fiscal union, an arrangement through which wealthier countries would make payments to support the Greek economy. Not coincidentally, this is the solution many economists have been telling European officials is the only way to save the euro — and which northern European countries have been resisting because it is so costly.

The three options laid out by the I.M.F. would have different operations, but they share an important feature: They involve other European countries giving Greece money without expecting to get it back. These transfers would be additional to the approximately 86 billion euros in new loans contemplated in Monday’s deal.

“Wait a minute,” you might say. “The I.M.F. isn’t calling for a fiscal union; it’s calling for debt relief.” But once a debt relief program becomes big enough, this becomes a distinction without a difference; they’re both about other eurozone countries giving Greece money.