Seoul, Aug. 16 -- South Korea's birth rate has dropped throughout much of the past decade, spelling trouble for the military as regional threats and global conflicts simmer.

A new report has found that the number of South Korean troops declined by 20% in the past six years, in large part because of the dwindling pool of young men - reflecting the shrinking workforce and swelling elderly population in one of the world's most rapidly aging countries, reports CNN.

The Defense Ministry report attributed the drop to "complex factors" including population decline and fewer men wanting to become officers due to "soldier treatment". Though the report didn't elaborate on that treatment, studies and surveys have previously highlighted the military'...