North Korea is planning to launch a rocket between April 4 and April 8. Pyongyang says the rocket will launch a communications satellite into orbit, but the United States, Japan and South Korea believe the launch is a cover for a long-range missile test.

Experts say there are several possible reasons why North Korea is launching a rocket. Jack Garrity, the executive director of the Asia Society, in Washington, says the government in Pyongyang wants to send a message overseas. "The prime objective is to show their independence to the outside world, and to make a point of undermining both the spirit and agreements of the six-party talks," he said.

Nicholas Eberstadt, a researcher at the American Enterprise Institute, believes there is also a domestic political reason for the launch. "(launching the rocket) stands to indicate the success of the regime's military-first politics program, and to strengthen the position of certain groups within the government," he said.

And there is likely a military incentive for the North to conduct this test, according to Gordon Flake, executive director of the Washington-based Mansfield Foundation. "It would introduce a lot more complexity into the security calculations for countries like the United States or China or others dealing with North Korea, because it extends the reach of their delivery capacity. That delivery capacity is far more important today than it was a couple of years ago, because of North Korea's successful nuclear test," he said.

The rocket North Korea is expected to launch in the coming days is theoretically capable of reaching the western United States.

South Korea, Japan and the U.S. say the launch will be a provocative attempt to advance Pyongyang's ability to deliver nuclear warheads with ballistic missiles. Those three countries and the European Union also say it will violate a U.N. resolution.

North Korea's Asian neighbors and the United States have been considering how to respond, and there are no easy answers.

South Korea has said that if the launch takes place, an international response will be inevitable. Japan says it will shoot down the rocket if it appears to threaten Japanese territory.

And 16 U.S. lawmakers, all minority Republicans, say they want President Barack Obama to authorize use of the U.S. missile defense system to shoot down any dangerous debris from the launch.

North Korea, meanwhile, says it will shoot down any U.S. spy planes if they violate Pyongyang's airspace, and Gordon Flake says attempts to intercept the North Korean rocket would only inflame the situation. "To pre-emptively shoot a North Korean missile on the launch pad, or to shoot it down over North Korean soil in initial stages, would be considered to be an act of aggression, I think, definitely by North Korea, but probably also by Russia and China," he said.

Flake says a pre-emptive shootdown would draw attention away from the North Korean violation of U.N. Security Council sanctions, and would highlight perceived U.S. or Japanese aggression.

Eberstadt, however, says the U.S. should shoot down the rocket or its debris if it can. "If our missile defense capabilities are adequate to destroy the launching missile, we should definitely destroy it. That would be a fine signal to our allies and to the DPRK that the ratching up of threats is not always necessarily credible by the Kim Jong-Il regime," he said.

Another question is how a North Korean rocket test would affect the six-party talks on ending Pyongyang's nuclear program. Jack Garrity says it might add urgency to the negotiations. "If anything, it probably gives a little bit of strength to the six-party talks, because all of the countries concerned realize that this is an ongoing issue and among the six parties, nobody really wants to see this occur, except for the North Koreans," he said.

But Eberstadt says the six-party talks are dead. "The six-party talks are pathetic. The six-party talks have been a sort of a zombie for the last four years, while the North Korean government has moved from one nuclear stage to a more advanced nuclear stage to yet a more advanced nuclear stage," he said.

Two previous Taepodong missile launches were unsuccessful, and Eberstadt and Garrity agree that a failed attempt would be a large setback for Pyongyang's nuclear program.

The United States has warned North Korea that it would face consequences if it launches a missile. But the Obama administration also says a path to return to international negotiations on an aid-for disarmament deal remains open.