A U.S. Congress think tank has pointed out that South Korea and Japan may feel compelled to have their own nuclear weapons should the United States fail to make the allies feel confident about the reliability and credibility of America's nuclear arsenal. 

The Congressional Research Service(CRS) made the remark in a recent update to a report entitled “Nonstrategic Nuclear Weapons,” where it noted the threats the two Asian countries face from their nuclear-armed neighbors such as China and North Korea. 

The report said some South Korean politicians have demanded the return of U.S. nonstrategic nuclear weapons to the Korean Peninsula and even called for self-nuclear armament in response to North Korea’s development and testing of nuclear weapons. 

It stated that although such views have not been supported by the incumbent South Korean government, they indicate that some may see U.S. security guarantees as fragile. 

The report also quoted experts as saying that extended deterrence requires more than U.S. nonstrategic nuclear weapons.