Pyongyang is known for being transactional and has long been willing to sell weapons to anyone who would pay. Its arms proliferation in the Middle East is well documented. A senior official with the Joint Chiefs of Staff in Seoul says they have evidence of North Korea exporting RPGs and potentially other weapons either directly or indirectly to Hamas; but the cooperation also likely extends to tactical doctrine and training. CNN's Paula Hancocks has the details. Featuring RUSI Associate Fellow, Dr Samuel Ramani.