**Congressional review of the July 2026 U.S.-Saudi 123 agreement faces procedural and substantive barriers that explain the 90% trader probability against entry into force this year.** The administration submitted the pact to Capitol Hill in late August, triggering a 90-day statutory clock under the Atomic Energy Act, yet recesses around the November elections have halted the count after minimal legislative days. Lawmakers can block or modify the deal via joint resolution of disapproval, and Democrats have introduced such measures citing gaps in IAEA Additional Protocol requirements and potential uranium enrichment pathways after a two-year study. President Trump’s public linkage of the agreement to Saudi normalization with Israel adds an unmet condition, while classified side letters and the need for possible resubmission to a new Congress in 2027 further complicate timely implementation. These factors sustain the current market consensus.