This is the 3404th most frequent Korean word.
대러
"대러" means "toward Russia" or "related to Russia."
In this sentence, "대러" is used as a prefix meaning 'against Russia,' indicating the target of the sanctions.
정부는 새로운 대러 제재를 발표했다.
The government announced new sanctions against Russia.
Here, "대러" is used as a descriptor meaning 'with Russia,' describing the relationships being discussed.
대러 관계가 최근 몇 년간 개선되기 시작했다.
Relationships with Russia have begun to improve in recent years.
In this context, "대러" means 'towards Russia,' describing the orientation of the strategy.