In the United States, it has been a tradition to formulate foreign policy doctrines to tackle challenges posed at the global level. These doctrines are almost always named after the President in whose regime they were outlined. So, when the Reagan administration formulated their foreign policy, keeping in mind the increasing influence of the Soviet Union in Asia, Africa, and Latin America, it began to be known as the Reagan Doctrine. It was the foundation on which American foreign policy was based from the mid-'80s to the end of the Cold War in 1991. On January 23, 1980, Reagan's predecessor and then President of the United States Jimmy Carter made it clear that the United States would not hesitate to use military force to defend its national interests in the Persian Gulf. The statement formed the basis of the Carter Doctrine, which came into being in response to Soviet Union's invasion of Afghanistan in 1979. At the behest of his National Security Adviser, Zbigniew Brzezinski, Carter made it clear that the Soviets should stay away from the Persian Gulf. As a part of this doctrine, the Carter-led American Administration began covertly arming the Mujahideen in Afghanistan to take on encroaching Soviets. Also in the picture was The Heritage Foundation, a Washington-based conservative think tank founded by bigwigs like Paul Weyrich and Edwin Feulner in 1973. When Reagan came to power in 1981, they published a report titled the Mandate for Leadership, which had nearly 2,000 suggestions to set America on the conservative path; more than half of these were adopted by the Reagan Administration within the first year in power. The Heritage Foundation soon became the brain of President Reagan's foreign policy, and at their behest, the White House decided to expand the Carter Doctrine and support anti-communist movements in Soviet-backed regimes in Asia, Africa, and Latin America. The Reagan Doctrine advocated the need to provide both, overt and covert support to anti-communist movements, in an effort to roll back Soviet-backed communist regimes in parts of Asia, Africa, and Latin America. Those in favor of this policy argued that it was the need of the hour to counter increasing Soviet influence in the world. For this, the Heritage Foundation identified nine countries, namely Afghanistan, Iran, Cambodia, Laos, and Vietnam in Asia, Angola, Ethiopia, and Libya in Africa, and Nicaragua in Latin America. While the aid for Mujahideen in Afghanistan had already begun during the Carter regime, the Reagan regime started off with Nicaragua and Angola. They decided to arm Contras against Soviet-bloc supported Sandinistas in Nicaragua and Jonas Savimbi's UNITA against People's Movement for the Liberation of Angola (MPLA) in Angola. Furthermore, when Congress repealed the Clark Amendment, which prohibited military aid to UNITA, aid began to flow overtly to the outfit. In Nicaragua though, the aid was covert, as the Boland Amendment prohibited assistance to the Contras. In order to raise funds to support the Contras, the US Administration went out of the way and facilitated the sale of arms to Iran, which was then under an arms embargo. Though the Reagan Doctrine was considered successful in Nicaragua, where the US-backed Contras were eventually successful in ousting Soviet-backed Sandinistas, things changed significantly when the Iran-Contra affair came to light. In 1989, the Soviet ended its occupation of Afghanistan, with Soviet leader Mikhail Gorbachev famously calling their war with US-backed Mujahideen a bleeding wound. In Nicaragua, the war came to an end with the loss of Sandinistas in the general elections in 1990. The Reagan regime even engineered the end of Soviet and Vietnamese occupation of Cambodia, by providing limited aid to Son Sann-led Khmer People's National Liberation Front (KPNLF). From the US perspective, it pitched the US as a global power. It was not the first time that the US had contemplated taking on the Soviet Union directly, but it was never pursued as policy makers feared that it would escalate the Cold War. There was a possibility of nuclear conflict as well. The stupendous success of the Reagan Doctrine allayed these and other such fears, and put the United States in command. Firstly, there was no direct involvement of American troops, and thus, no casualties. Secondly, arming anti-communist movements to topple communist regimes in different parts of the world cost the US less than what the Soviet had to spend in putting these regimes there in the first place. So, it was a win-win situation for the United States. For the Soviet Union, on the other hand, the cost of all these conflicts was crippling. The Reagan Doctrine brought an end to Soviet expansion under the garb of the Brezhnev Doctrine, which stated that the Soviet Union had the right to intervene in the affairs of Communist countries when hostile forces tried to turn the development of some socialist country towards capitalism. In essence, the Reagan Doctrine was America's fitting reply to the Soviet Union's Brezhnev Doctrine. The Reagan Doctrine was subjected to severe criticism when the Iran-Contra affair revealed how the US had gone out of its way to reach its goal during the Reagan presidency, with some people even claiming that the president knew everything all along. It didn't just end there though. By providing arms to less-known militants―some of which had dubious human rights records―the American Administration had only strengthened them. What they didn't contemplate was a scenario where these militants would turn hostile towards the US itself. That did eventually happen. The US had directly or indirectly contributed in the making of Al Qaeda, which came to haunt it at the dawn of the 21st century. Even Pakistan, via whom the US aid to the Mujahideen was facilitated, eventually put its interest first, and created Taliban to pursue a proxy war with India. Such was the impact of the Reagan Doctrine that it was adopted by Reagan's successor, President George H.W. Bush. It continued to influence US foreign relations until the end of the Cold War in 1991.