National security bill comes into law on March 23NY tightens security in subways as crimes riseU.S. chip firms urge Biden administration to approve sales to China as ban backfiresOfficials refute soEnvironmental legal cases down last yearXi congratulates Zardari on election as Pakistani presidentChina applauds Arab League's adoption of ChinaU.S. chip firms urge Biden administration to approve sales to China as ban backfiresXi emphasizes no letup in drive to combat air pollutionWashington manipulates freedom of speech, report finds