North Korea has tight control on the civilian population and frequently executes political dissidents. It appears like it would be difficult to assemble and arm an opposition to the current regime due to the tight government control. Is there an armed opposition within North Korea that could be supported by an International coalition? If not is it possible to assemble one?
There have been some reports of organized resistance against the North-Korean regime, such as pamphlets being spread and black markets in goods and information. There also are some people who are trying to organize such movements from outside North-Korea. Of course, none of this is the same as "armed opposition", but this seems to be the entire extent of domestic organized opposition against the regime.
It's possible but unlikely that a significant armed rebellion escaped Western attention. North-Korea is secretive, but an armed rebellion is not easy to keep secret. There is (and always has been) a steady stream of North-Korean defectors providing information, tourism in North-Korea is also a thing, and many observers from South-Korea as well as the rest of the world are closely watching the country. An armed rebellion would not be easy to hide.
The big question is of course "why not?", and that seems to be a bit difficult to answer conclusively. It's not like there are polls we can reference for this ;-)
- repression due to an extremely oppressive and brutal police state;
- harsh living conditions and social engineering which prevents a middle class-like population from arising which can organize opposition;
- pervasive propaganda.
Note that recently some people have claimed that the North-Korean regime is crumbling, see the "black markets" link at the top. Time will tell if they're correct, but thus far the North-Korean regime has been remarkably effective at preventing any significant domestic opposition.
Yes, the N Korea Military in some real ways opposes the Communist Party apparatus.
According to A Study on the Party-Military Relations of the Kim Jong-Un Regime, a report commissioned by the S Korean government:
North Korean armed forces may demand for a military-centric government or reshape the current political order if the Kim Jong Un regime is unable to tackle the country’s failing economy, South Korea’s Yonhap News Agency reported, citing a Seoul-commissioned report. Pyongyang has been hit with international sanctions following its nuclear and missile tests in January and February, leading to its crippling economy.