門戸 もんこ開放 かいほう政策 せいさくじゃなかったです
monkokaihōseisakujanakattadesu

Noun
Desu Copula

The polite, past negative form of 門戸開放政策

1. Open-door policy wasn't.; Wasn't an open-door policy.

Past/Perfective
Negative
Polite
Casual Register