A large number of tanks and armored vehicles were seen arriving Thursday at Russia's 18-kilometer-long border with North Korea along with thousands of troops who traveled by train from a military base in Vladivostok. The massive Russian deployment is to prevent a possible influx of hundreds of thousands of North Koreans in the event of war between Washington and Pyongyang. China has dispatched over 150,000 troops to its border with North Korea for the same reason.