well I guess they have passed pretty severe sanctions against North Korea but they have no one yet who's willing to actually board North Korean ships and seize the sanctioned items.
If there is a confrontation, it will be set off by probably a US ship attempting to board a North Korean vessel, to seize parts for their weapons program. China and Russia have stated they have no interest in boarding North Korean vessels.
Here are the UN sanctions that have gone into effect, but no one is enforcing yet.http://en.wikipedia.org/wiki/United_Nations_Security_Council_Resolution_1718
North Korea must "not conduct any further nuclear test or launch of a ballistic missile", "suspend all activities related to its ballistic missile programme" and "abandon all nuclear weapons and existing nuclear programmes in a complete, verifiable and irreversible manner".
The DPRK must also "return immediately to the six-party talks without precondition".
Shipments of cargo going to and from North Korea may be stopped and inspected for weapons of mass destruction or associated items (however, there is no obligation placed on member states to perform such inspections).
A ban is placed on imports and exports of "battle tanks, armoured combat vehicles, large calibre artillery systems, combat aircraft, attack helicopters, warships, missiles or missile systems", "related materiel including spare parts" and any other items identified by the sanctions committee.
UN member states must freeze the overseas assets of individuals and companies involved with the DPRK's weapons programmes. An international travel ban is also placed on programme employees and their families.
UN members are banned from exporting luxury goods to North Korea.
I guess the government military cronies selling stuff to North Korea don't really want to lose a customer. I think North Korea got a big contract to drill into Iraq's virgin oil fields, they got a nice chunk of the UN war booty. They are all in on it together you know.