連合れんごうこくぐん最高さいこう司令しれいかんそう司令しれいだったら
rengō koku gun saikō shi reikan sō shire ibudattara

Noun
Da Copula

The "-tara" conditional form ("if/when…") of 連合国軍最高司令官総司令部

1. If/When it were the Supreme Commander of the Allied Forces General Headquarters:; ; If/When it had been the Supreme Commander of the Allied Forces General Headquarters:

Tara Conditional