Vietnam is located on the easternmost edge of the Indochinese Peninsula, with China to the north and Laos and Cambodia to the west. Its more than 2,000 mile-long coastline abuts the Gulf of Tonkin, the South China Sea and the Gulf of Thailand. These seas create both direct access to the wider Pacific Ocean and a critical buffer to Vietnam's long and narrow land territory. Modern Vietnam consists of two geographic and population cores — the Red River Delta in the north, home to the capital of Hanoi, and the Mekong River Delta in the southern lowlands, where Ho Chi Minh City sits. These cores are separated by over 1,600 miles and connected by a thin and largely mountainous coastal spine, only around 30 miles wide at its narrowest point. Despite mountains and jungles, the northern Vietnamese core has a long history of invasion by forces from China. This almost continuous pressure from the north in part forced Vietnam's early rulers to expand the country's boundaries, first southward, to the Mekong River Delta, and then westward, into present day Laos and Cambodia. Historically and today, the natural geographic separation of Vietnam's northern and southern cores has exacerbated the two regions' social, cultural and political divide — leaving the country vulnerable to invasion by foreign powers, whether Chinese, French or American. Vietnam’s primary geographic challenge is to secure buffer space both on land and sea. Today, Vietnam's need for space and security in the South China Seas pits it against China, also in the throes of maritime expansion, thus adding a new dimension to Vietnam's longstanding struggle to carve space for itself against its larger northern neighbor.