 Externally, the Han dynasty neutralized the threat posed by the nomadic Xiongnu following a series of wars.The boundaries of China was extended into what is modern-day western Xinjiang, South Korea (near Seoul), and Vietnam (around Huế).The Silk Road emerged as a major route that connected the East and the West after the Han diplomat Zhang Qian established contact with the numerous Central Asian tribes, thus facilitating commerce and cultural exchanges.