Google data shows a surge in searches for “WWIII” and “US draft age limit” as Middle East tensions grow, reflecting worries about conscription. Although the U.S. ended the draft in 1973, “federal law preserves guidelines for reactivating the system in times of emergency.”

The Selective Service keeps records of about 16.4 million men aged 18–25. “Men aged 20 would be the first to be drafted,” followed by older and younger groups. Citizens, immigrants, refugees, and even undocumented men must register. Transgender people assigned male at birth are also included.

Registration is simple through the Selective Service website or post offices, but failing to register can bring “five years in jail and fines of $250,000,” along with losing federal aid, jobs, or voting rights.

If Congress and the President authorize it, a public lottery would determine who is called first. Those selected undergo medical, psychological, and family-status reviews, with many granted deferments or non-combat roles.

For now, the military remains “entirely voluntary.”