Entente Cordiale

The global revelation of the Royal Navy's space navy at the turn of the century nudged the French into an Anglo-French agreement of cooperation and mutual colonial freedom.

Consequences

The most obvious outcome was the rapid construction of the Loubet Tunnel for atmospheric trains, and the continuation of the line via Paris to Nice on the Mediterranean.

It also resulted in the entry of the UK into war with Germany when that country opened fire on Tangier, owned by France, in 1911.

Real world

This event takes place some four years before the agreement was signed in our world.