Sino-North Korean Mutual Aid and Cooperation Friendship Treaty

The Sino-North Korean Mutual Aid and Cooperation Friendship Treaty is a treaty signed on 11 July 1961 between North Korea and China. The treaty is currently the only defense treaty China and North Korea has with any nation.
Background.
After the 1961 May 16 Coup, the new South Korean leader Park Chung-hee urged for an increase in military spending and for action to be taken against North Korea. The North Korean leadership feared a South Korean invasion and turned to the Soviet Union and China for support.
Signing.
The treaty was signed in Beijing and came into effect on 10 September of the same year. Premier of the People's Republic of China Zhou Enlai and Prime Minister of North Korea Kim Il-sung signed for their respective countries. The treaty generally promoted peaceful cooperation in the areas of culture, economics, technology and other social benefits between the two nations. Specifically, Article 2 of the treaty declares the two nations undertake all necessary measures to oppose any country or coalition of countries that might attack either nation.
The treaty remains in effect and automatically renews every 20 years, being renewed in 1981 and 2001. The most recent renewal will remain in effect until 2021. The right to cancel the Sino-North Korean Treaty can be invoked at specified five-year intervals, and each party must give advance notice of one year.
Kim Il-sung arrived in Beijing in 1961 to sign the treaty just a few days after signing the "North Korean-Soviet Mutual Aid and Cooperation Friendship Treaty" (). The Soviet treaty however has not been in effect since the 1990s with only a revised "consultation" treaty being re-adopted in 1999.