The United States did not carry out a lasting overhaul of immigration policy after the 9/11 attacks, according to a new analysis of federal survey data.
Nearly 25 years after the September 11 terrorist attacks, immigration from predominantly Muslim countries has increased dramatically in the United States, per a new Center for Immigration Studies analysis.
The report uses Census Bureau data to estimate that the foreign born population from majority Muslim nations rose from 1.7 million in 2001 to 3.4 million in 2024. That is an increase of 1.8 million people and a gain of 103 percent.
The Census Bureau does not ask individuals about religious affiliation, so the report does not claim that every person included in the count is Muslim. Instead, it examines immigrants who were born in countries with predominantly Muslim populations.
The findings indicate that the United States did not make a decisive, lasting change to immigration policy after September 11. Despite heightened attention to terrorism and screening in the immediate aftermath of the attacks, migration from the Muslim world continued to grow.
The increase also exceeded the growth of the total foreign born population, which rose 58 percent from 2001 through 2024. It was nearly seven times faster than the increase in the American born population over the same period.
Most of the growth appears to result from lawful immigration programs rather than illegal immigration. The report estimates that illegal immigrants represent roughly 10 to 20 percent of immigrants from majority Muslim countries, compared with an estimated 25 to 30 percent of the total foreign born population.
Afghanistan saw one of the largest gains. The Afghan born population in the United States rose by approximately 202,000, or 476 percent, from 2001 through 2024. The report says that Afghan admissions following the American withdrawal from Afghanistan helped drive more recent growth, although Afghans represented about one quarter of the wider increase since 2020.
Significant growth was also recorded among immigrants from Pakistan, Iran, Syria, Yemen, and Somalia. The report notes that several leading source countries have troubled relations with Washington or face serious threats from terrorist groups and political instability.
The report also estimates that 1.9 million American born people had at least one parent from a majority Muslim country in 2024. Together, the foreign born population and their American born children totaled 5.4 million, compared with 2.5 million in 2001.
Using a straight line projection based on recent population growth, the report estimates that this combined population could reach 10.4 million by 2050. The authors caution that forecasts are uncertain because future admission rules, fertility patterns, and economic conditions could change.
America First policy should begin with the understanding that border enforcement and immigration limits are national security necessities. The September 11 attacks showed that weak screening and a permissive admissions system can carry devastating consequences, so immigration must be severely curtailed and ultimately ended to reduce exposure to terrorism, crime, and wider social instability.
