When the September 11th attack happened on New York several years back, the then US President, George Bush, was given a red carpet option to handle the terrorist issue effectively. But Bush instead of using the local bully Pakistan to tackle the Afghanistan and Iraq issue, he chose to handle the hot issue himself, and ended up only with lot of negative points. He made the entire Muslim world, and even other world powers like China and Russia, see a weak US. The incapability of the US intelligence agencies in reading the terror network and their movement, lead to also loss of over 4000 US + NATO forces. The wrong assessment of the problem and the wrong military approach to the issue was supported by the then British PM Tony Blair, who eventually lost his job in a merciless manner.

Now Barack Obama is doing the scavenging job of clearing all the bad names created for US and its allies.

Again, North Korea is paving a neat and effective option for Barack Obama to correct all the past errors and make the entire world respect US as the supreme power in terms of military and also intelligence and also firm action.
By provoking US / Japan / South Korea blatantly in the last few weeks, North Korea is giving a plateful of lovely options for Barack Obama, which can be decisively met by US through various means. The first option of UN sanction has been already used and US needs to just get other countries in implementing the resolution aspects.
US needs to be totally alert with all the action plans for various scenarios ready for execution in minutes of any eventual action from North Korea.
For example, if there is an unprovoked long range missile launch from North Korea, then US must be ready with all the options including strong and decisive military retaliation , which must be short but very powerful. That means using the right kind of aerial routes and tools, and selecting all the important targets inside North Korea.
By doing that, US will be able to convince the world (excluding certain power centers in China and Russia who are tacitly supporting North Korea), that it has only acted in self-defense, and also keep the options open for North Korea to voluntarily come to the negotiation table, on US terms.
And it will be prudent for Barack Obama to see the North Korean issue as a Korean regional issue, and provide strong and quick fire support to South Korea in handling the issue. By using the local expert in handling the issue, US will be able to pull the string on North Korea the way it wants.
By making North Korea kneeling down, US will also be able to send strong message to Russia and China, more particularly China, which is using indirect means to gain global military status.
If you take history, US has been failing in its direct military intervention , right from Vietnam, Iran, Iraq and Afghanistan. So Barack Obama has to find a better and quicker way to regain global supremacy.