North Korea's fifth nuclear test on Sept. 9 — its second this year — and its raft of missile tests have left nations groping for an appropriate response, one that could arrest Pyongyang's inexorable march toward atomic disaster.

Numerous rounds of sanctions, formal talks and fleeting agreements by countries and groupings have failed to induce the North to give up its nuclear weapons program. The U.S. policy of "strategic patience" under the administration of President Barack Obama — in which Washington has attempted to wait out a sanctions-crippled Pyongyang — has yielded few gains.

Some observers even believe the policy may have had the opposite effect, fueling leader Kim Jong Un's drive to create missiles capable of delivering atomic bombs to U.S. and Japanese shores, something the regime views as key to its survival.