Oceania Union and United States of South America both gladly recognized PLANT's independence and accepted PLANT's offer of neutrality, in exchange for continued trade and good relation between them.
Alliance feared this pro-PLANT USSA might let ZAFT stations troops and weapons on South America, further threaten nearby Earth Alliance territory. To deny PLANT agricultural resources and seize the strategically important location Panama, the Earth Alliance launched the invasion of United States of South America on February 19th, one day after USSA recognized PLANT's independence. The Alliance also seized the strategically vital Porta Panama space port and its mass drivers.
On February 20th, the Oceania Union, despite its geographical remoteness, also received declaration of war.
