Stoltenberg NATO Secretary General Jens Stoltenberg discusses the alliance with Brookings Institution's Mike O'Hanlon at Georgetown University in Washington during a Brookings Institution/Georgetown University event. Stoltenberg stressed the need for unity in the trans-Atlantic alliance as the world faces new threats. SHARE IMAGE: Download Image: Full Size (0.64 MB) Tags: NATO Photo By: NATO VIRIN: 211005-O-D0439-001.JPG Photo Gallery