From this New York Times article concerning Jehovah's Witnesses and conscientious objection in South Korea. Excerpt:
Over the years, Jehovah’s Witnesses have filed a series of appeals asking the Constitutional Court to rule that the Military Service Act violates the constitutional right to freedom of conscience and religion. Hopes for an end to their travails rose in July, when the court held a public hearing on multiple appeals only four years after it had rejected similar petitions. The court is likely to rule on the matter before the end of the year.Comparative law note: The United States has long recognized conscientious objection, including in-service objectors. While these cases can be challenging, the system -- which is subject to judicial review by writ of habeas corpus in the civilian federal courts -- has seemed to be able to distinguish between those who are sincere and those who are not.