That country continued to develop economically while increasing its military power.
As a result, they are pressuring other countries both economically and militaristically with both of these powers.
ご質問ありがとうございます。
"That country continued to develop economically while increasing its military power"=「その国は経済的に成長すると共に軍事的な力を増強していった。」
"As a result, they are pressuring other countries”=「結果、彼らは他国を圧迫している」
"both economically and militaristically with both of these powers."＝「彼等の経済力、そして軍事力により。」
ご参考に。
アメリカ合衆国 
