Iberian outage restored within a day; three-month blackout frame mixes unlike failures

The April 28, 2025 disturbance disconnected Spain and Portugal from stable supply and briefly affected southern France. Red Eléctrica de España and REN restored most demand within roughly a day, not a season. ENTSO-E's subsequent factual record, as summarized in its October 2025 reporting, described a cascade tied to voltage and generation disconnection rather than a storm or fuel cutoff. That is an operational failure on a synchronized European grid with neighbors, black-start assets, and spare energy. It is not evidence that a rich system's bulk network stays down for three months.

NERC's long-term reliability assessments, including the December 2024 edition and the January 2026 update cited in secondary coverage, flag elevated resource-adequacy risk where retirements and demand growth outrun accredited additions. That metric is loss-of-load expectation over peak hours, not a quarter-long islanding of the transmission system. Separately, the Department of Energy and industry surveys have put large power transformer lead times near or above two years, with some generator step-up units longer. Wood Mackenzie's supply-gap estimates describe a procurement bottleneck. Hardware delay slows repairs after damage; it does not by itself keep an intact grid dark.

Interests split by actor. Utilities gain rate base from data-center load and lose margin if coal and gas retire before firm capacity and voltage support are replaced. Washington gains from onshoring transformers and electrical steel and pays in longer lead times when tariffs shrink the supplier set. Madrid gains lower gas exposure from inverter-based plant and pays if reactive-power performance misses the grid code. Havana states that the US embargo and aging units cause the deficit; the sanctions regime is real, and Unión Eléctrica's own notices still show unmet megawatts.

What the source collapses into one fragility story is three ledgers. Europe's next move is institutional: tighter connection requirements and voltage-control obligations, which ENTSO-E and national regulators can write faster than new thermal plant can be built. The US constraint is industrial: interconnection queues and transformer manufacturing, not a missing cultural memory of outages. Cuba's constraint is fuel and maintenance under a state monopoly and a sanctions regime, a condition already measured in daily deficits rather than a hypothetical. A three-month regional blackout remains a low-probability case; the documented near-term risk is repeated shortfalls and slow replacement.