Both countries have held up their fists towards the other country for some time, and they can't take them down now.
Both countries have been on the offensive for a long time now, and neither of them are willing to back down.
ーBoth countries have held up their fists towards the other country for some time, and they can't take them down now.
「両国とも相手国に振り上げた拳を下ろせなくなっている。」
hold up one's fist で「拳を振り上げる」
take ... down で「…をおろす・下げる」
ーBoth countries have been on the offensive for a long time now, and neither of them are willing to back down.
「両国とも長い間攻勢的で、どちらも折れる気がない。」
offensive で「攻勢の・侮辱的な・攻撃的な」
back down で「折れる・手を引く・取り消す」
ご参考まで!