Book excerpt: 1. The United States of America, through its departments and agencies, regulates the activities of foreign individuals and entities in and affecting the United States in order to prevent, disclose, and counteract improper foreign influence on U.S. elections and on the U.S. political system. U.S. law bans foreign nationals from making certain expenditures or financial disbursements for the purpose of influencing federal elections. U.S. law also bars agents of any foreign entity from engaging in political activities within the United States without first registering with the Attorney General. And U.S. law requires certain foreign nationals seeking entry to the United States to obtain a visa by providing truthful and accurate information to the government. Various federal agencies, including the Federal Election Commission, the U.S. Department of Justice, and the U.S. Department of State, are charged with enforcing these laws.