Tens of thousands of Afghan refugees will soon need to find new homes, and many countries are preemptively closing their doors.

Why it matters: The U.S. is leading what the White House calls one of the biggest airlift in history as Afghans flee from Taliban rule. That exodus will quickly become a humanitarian crisis involving the U.S., Europe and parts of Asia and the Middle East.

What to watch: The U.S. is preparing to bring in 50,000 Afghan refugees in the next year, Bob Kitchen, vice president of emergencies and humanitarian action at International Rescue Committee (IRC) told Axios.

• That's more than the total, annual number of refugees the U.S. has resettled from all over the world over the past couple years.
• IRC is one of the largest resettlement agencies in the U.S., and typically handles 25% of refugee arrivals Kitchen said. "We're now currently staffing up and getting ready to handle the 25% of 50,000 new arrivals."

Several European countries are also flying Afghans out of the country. But there's already concern in the EU about another major wave of migration.

• French President Emmanuel Macron has said Europe must "protect itself" from an influx of Afghan migrants.
• Greece has completed a border fence with Turkey, in an effort to deter Afghan migrants.
• Turkey, which hosts millions of Syrian refugees, has also beefed up its own border security with walls, ditches and barbed wire in the wake of Kabul's fall to the Taliban.
• Australia has launched a campaign urging Afghans not to attempt to make the dangerous voyage to the country by sea. The country has pledged to take in just 3,000 Afghan refugees.

What to watch: Afghans who don't make the cut to get airlifted out by the U.S. are expected to flee to neighboring countries, including Iran and Pakistan.

• As of the end of 2020, Pakistan already had 1.4 million Afghan refugees living in the country, according to UN figures. As of this year, Iran had 780,000 Afghan refugees on top of 2.3 million undocumented Afghans.
• The Taliban have provided conflicting messages about their willingness to allow Afghans to leave, and Pakistan is currently only allowing those with Pakistani visas to cross land borders, Kitchen said.

The big picture: Decades of war created an Afghan refugee crisis long before the U.S. began to withdraw military forces. Millions of people had already fled the country or were displaced within its borders.

• "The the notion of an Afghan refugee situation is not at all new. It's four decades it has been going on," U.N. High Commissioner for Refugees spokesperson Chris Boian told Axios.