Gen. Michael Flynn, President Trump’s national security advisor, resigned on February 13 after it was revealed he had misled White House officials about his conversations with the Russian ambassador to the United States.  Flynn had been under scrutiny for privately discussing U.S. sanctions against Russia with that country’s ambassador to the United States during the month before President Trump took office, which would be a violation of federal law (the Logan Act). But what are sanctions, and why do we have sanctions against Russia?

Here are ten things you should know about international sanctions:

1. In foreign policy, sanctions refer to coercive measures taken by either nations or international bodies (either unilaterally or multilaterally) for the purpose of deterring, punishing, rehabilitating, or shaming foreign countries or foreign nationals into changing their behavior. Sanctions generally take one of five forms: diplomatic, economic, military, sports, or individual.

2. Diplomatic sanctions are sanctions characterized by political disengagement, such as closing an embassy, withholding recognition from a particular regime, or recalling diplomatic representatives (e.g., an ambassador) from a foreign country either temporarily or permanently. Diplomatic sanctions are frequently paired with other forms, such as military sanctions (used against Germany and Japan in World War II) or economic sanctions (in about 30 percent of the cases in which the U.S. imposes economic sanctions, diplomatic sanctions are also implemented).

3. Economic sanctions are the withdrawal of customary trade and financial relations for foreign and security policy purposes. (“Customary” refers to the levels of trade or financial activity that would probably have occurred in the absence of sanctions.) Economic sanctions can take numerous forms, including freezing of economic assets, restraints on capital, restrictions on trade, and reductions in foreign aid.

4. Military sanctions are sanctions that either include military intervention or target a foreign military. The most common type of this sanction is an arms embargo (a narrow form of economic sanction) which may prevent the sale or exchange of weapons, defensive tools, or dual-use technologies (i.e., technology that can be used for both peaceful and military aims).

5. Sports sanctions attempt to prevent the population of a particular nation from participating in national, pan-regional, or international sporting events. This form is extremely rare and even more rarely effective. For example, United Nations Security Council Resolution 757 (1992) prevented the Yugoslavia football team from playing in the Euro 1992 finals, but Yugoslav athletes were permitted to compete in the 1992 Summer Olympics as “Independent Olympic Participants.”

6. Individual sanctions are prohibitions put on specific foreign nationals because of their economic or political ties to particular foreign nations or entities. Per U.S. law (22 U.S. Code § 2798) the president can impose certain procurement and import sanctions on non-citizens if they are involved or associated with certain activities (e.g., using lethal chemical or biological weapons against fellow nationals).

7. Prior to 1990, the U.N. Security Council imposed sanctions against just two states: Southern Rhodesia (1966) and South Africa (1977). But as Jonathan Masters notes, since the end of the Cold War the Council has used sanctions more than twenty times, most often targeting parties to an intrastate conflict, such as in Somalia, Liberia, and Yugoslavia.

8. Most of the U.S. sanctions programs are administered by the Treasury Department’s Office of Foreign Assets Control (OFAC). OFAC was formally created in December 1950 following the entry of China into the Korean War, when President Truman declared a national emergency and blocked all Chinese and North Korean assets subject to U.S. jurisdiction. Currently, OFAC administers 26 different sanctions programs. As Masters observes, the United States uses economic and financial sanctions more than any other country.

9. In the United States, sanctions can be imposed by either the legislative branch (through legislation) or by the executive branch (through executive orders). The laws that allow the president to impose economic sanctions are the National Emergencies Act, which allows the executive to declare a national emergency, and the International Emergency Economic Powers Act (IEEPA), which allows the executive to regulate commerce after declaring a national emergency.

10. Some sanctions against Russia that President Trump could lift began on March 6, 2014, when President Obama, in Executive Order 13660, declared a national emergency to deal with the threat posed by the actions and policies of certain persons who had undermined democratic processes and institutions in Ukraine; threatened the peace, security, stability, sovereignty, and territorial integrity of Ukraine; and contributed to the misappropriation of Ukraine’s assets.

According to OFAC, in further response to the actions and polices of the Government of the Russian Federation, including the purported annexation of the Crimea region of Ukraine, President Obama issued three subsequent executive orders that expanded the scope of the national emergency declared in Executive Order 13660.

Together, these orders authorize the imposition of sanctions against persons “responsible for or complicit in certain activities with respect to Ukraine; against officials of the Government of the Russian Federation; against persons operating in the arms or related materiel sector of the Russian Federation; and against individuals and entities operating in the Crimea region of Ukraine.” Executive Order 13662 also authorizes the imposition of sanctions on certain entities operating in “specified sectors of the Russian Federation economy” while Executive Order 13685 prohibits the “importation or exportation of goods, services, or technology to or from the Crimea region of Ukraine, as well as new investment in the Crimea region of Ukraine by a United States person, wherever located.”

Joe Carter is an adjunct professor of journalism at Patrick Henry College, an editor for several organizations, and the author of the NIV Lifehacks Bible.

Photo Credit: Five-Roubles Coins. By Waltie, via Flickr.