My own territory considered 'foreign land'?

[Vicar of Christ]

Through a convoluted series of events Japan war with the Soviet made china spill into war with France. Northern Indochina was overrun but I landed back in Hanoi to try to cut the chinese forces moving south... However my plans were dashed because once I secured Hanoi and its immediate surrounding it would not let me repair infrastructure or build an airfield. The tool tip said it was because it was 'foreign land'.

What gives?

 

[Alpha2518]

Through a convoluted series of events Japan war with the Soviet made china spill into war with France. Northern Indochina was overrun but I landed back in Hanoi to try to cut the chinese forces moving south... However my plans were dashed because once I secured Hanoi and its immediate surrounding it would not let me repair infrastructure or build an airfield. The tool tip said it was because it was 'foreign land'.

What gives?

Probably because they control the state. Take more of it over.

 

[SchwarzKatze]

Hover the state control flags and see how many % you and your enemy control