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 square, rest assured it