The Obama administration is wrestling over whether to send an aircraft carrier to take part in military exercises with South Korea in what would amount to a significant show of force after the deadly sinking of a South Korean warship in March.

The back-and-forth over the USS George Washington reflects the precarious security situation in Northeast Asia following the North Korean sinking of the Cheonan on March 26.

It also underscores a huge issue facing U.S. and South Korean officials: how to stop North Korea, which is now believed to possess nuclear weapons, from conducting conventional attacks such as the torpedoing of the Cheonan.

Some within the administration are arguing that dispatching the 97,000-ton carrier to the Yellow Sea off the Korean Peninsula, where North Korea sank the Cheonan, could anger China or cause North Korea to react violently, according to officials involved in the discussions.

But others insist that the United States needs to send a clear message to its allies and to North Korea and China that the United States is standing firmly behind the South.

“It’s a very tough call,” said Susan Shirk, a former State Department official and an expert on Asian security at the University of California at San Diego.

“You don’t want to be too proactive. But you need to send a clear message.”