Discuss as:  Syria's chaos complicates task for chemical weapons
investigators  What should be the response if Syria deploys
chemical weapons? Channel 4's Jonathan Miller reports.
Prospects for a quick conclusion to a U.N. investigation of a
possible chemical weapons attack in Syria will depend on
cooperation from the warring parties and safety for
investigators — problematic conditions in the chaos of the
country's civil war, an expert on weapons control told NBC News
on Thursday.  Secretary-General Ban Ki-moon said Thursday that
he had agreed to conduct an investigation of allegations of an
attack in the northern city of Aleppo. The government and the
opposition have accused each other of carrying out that attack
on Tuesday.  Ralf Trapp, a German who works on disarmament and
non-proliferation issues, specializing on chemical and
biological weapons, said the first job of an inspection team
would be safely getting to and operating at the site. He said
then -- if the Syrian parties cooperated and the inspecto