The right to reject tribunal ruling is real
After the Philippines filed a case in The Hague-based Permanent Court of Arbitration against China in the South China Sea dispute, Beijing has made it clear that it would neither participate in nor accept the ruling of the arbitral tribunal. But despite the extensive international support it has received, Beijing's "non-participation and non-acceptance" stance has been criticized by some Western countries.
There is, in fact, a precedent of "non-participation and non-acceptance" of a ruling by a third party to settle an international dispute. In the Nicaragua case of the 1980s, the then Ronald Regan-led US administration took a "non-participation and non-acceptance" stance when the International Court of Justice accepted the case; it eventually passed a ruling that went against the US.
Subsequently, although Nicaragua submitted the case twice to the United Nations Security Council for discussion, the US used its veto as a permanent Security Council member to foil its passage. Noticeably, the Security Council's members such as Britain and France and Thailand, too, refused to support Nicaragua's demand for the implementation of the ICJ ruling, by abstaining from voting on the discussion under various pretexts. By abstaining from voting, these countries indicated they, as Security Council members, chose to take into consideration extensive political factors, though they could support the ICJ verdict.