most being used as a protective barrier around the perimeter of times square to ward off a truck style attack. we live in a changing world now. as i said before, it just can t be about what happens in new york. reporter: the nypd is in constant communication with foreign departments gaining intelligence and sharing police strategy with cities abroad. in london, there s added security at the changing of the guards. heavily armed police were unavoidable in berlin as they stood post behind concrete barriers at a christmas concert. czech holiday markets were heavily patrolled. in france, the government announced a boost of 10,000 soldiers on the streets over the holiday period, adding to the officers working around the clock. we are really giving of ourselves, of our time and at a cost to us and our families. reporter: nearly two million people are expected in times square t extra police presence a noticeable addition to keep new york city safe. if you are coming down to times sq