missles that were launched over Japanese territory

一丸となって高度な警戒態勢を維持する the gov acts as one inmaintaining its high level of vigilance

黙々と任務にあたる concentrate fully on performing one’s duties

最前線で任務にあたる人 A who are charged with duties at the front line

機雷掃海 minesweeping

果たすべき役割を全うする perform the roles you should

それぞれの持ち場において each in your own capacity

諸君の活躍に大いに期待しています i have great expectations for your active engagement