Wow! UN is so good at investigating chemical weapons and ballistic missiles now.

https://sg.news.yahoo.com/un-experts-north-korea-sent-banned-chemical-items-020946519.html

UN is accusing North Korea of exporting chemical weapons to Syria and ballistic missiles to Myanmar.

If UN was so good at investigation, then it should know about Iraq's non-existent of WMDs.  Why did UN allow US's unilateral invasion of Iraq then?