Nuclear weapons could embolden North Korea to freely engage in various military provocations and the United States should be prepared for the possibility of limited war with the communist nation, a U.S. expert said Thursday.
  

Van Jackson, a visiting fellow at the Center for a New American Security, issued the warning in a statement submitted for a hearing of the House Foreign Affairs Committee's Asia and the Pacific subcommittee, saying the North has now become a de-facto nuclear power.
  

"North Korea is not only now a de facto nuclear state, but the size of its arsenal is unknown, and Pyongyang is progressing toward its own version of a secure retaliatory nuclear strike capability," Jackson said.
  

The U.S. goal of preventing the North from becoming a nuclear state has "visibly failed," he said.
  

"North Korea may soon believe it has a free hand to engage in various forms of coercive violence and military adventurism precisely because it thinks it has a nuclear deterrent against major war," the expert said.
  

Jackson, who served as a strategy adviser and a senior country director for the Pentagon from 2009 to 2014, said that in order to manage the North Korean nuclear threat, the U.S. "must embrace the possibility of limited war and plan accordingly."
  

"The United States cannot reasonably be expected to capitulate to North Korean demands and simply recognize it as a nuclear power, nor should it launch a preventive war to disable North Korea's nuclear capability at this point in time," he said.
  

The suggestion is similar to what the Center for a New American Security said in a policy suggestion to new Secretary of Defense Ashton Carter earlier this month. The report said the U.S. should be prepared for "limited-war scenarios" with the North in case a diplomatic solution to the North's nuclear program fails.
  

In the statement for the House hearing, Jackson said the U.S. should also be prepared for the North's cyber-capability that he said is "lethal" in conjunction with other weapons systems. North Korean drones are also a threat because such unmanned planes can penetrate South Korean airspace undetected and be used as a weapons delivery system, he said.
  

"Still more dangerous are developments in North Korea's ballistic missile program. It has been reported that North Korea's short-range Nodong ballistic missiles, once thought primarily useful for striking bases in Japan because of their range, have now been tested at new launch angles that allow it to fire against South Korean targets as well," he said.
  

Jackson also noted that the North's road-mobile intercontinental ballistic missile, KN-08, poses a unique problem for the U.S. because it would be difficult to physically locate and target the missiles, which could leave U.S. bases and potentially U.S. territory vulnerable.
  

The North may also be developing long-range sea-launched ballistic missiles, he said. (Yonhap)