WASHINGTON -- The United States has fought two wars after Sept. 11, 2001, has installed countless bollards and surveillance cameras, and weathered many other terrorist-related threats since then.

But the day is now almost at hand when the federal government will at last require that passengers boarding airplanes in the United States use new forms of "real" ID cards that, the government says, will improve aviation security.

The Transportation Security Administration (TSA) has launched a new public information campaign to prepare people for when the new Real ID requirement takes effect next fall. When the Oct. 1, 2020, deadline arrives, all airline passengers will have to show a Real ID-compliant form of identification to board an airplane or enter a TSA checkpoint.

Those who lack a Real ID or other acceptable form of identification, such as a valid passport, will be out of luck. The TSA says those folks will not be allowed to fly.

Several states, such as Pennsylvania, New Jersey and Oregon, have received extensions from the Department of Homeland Security (DHS). California's level of compliance has been under review since DHS informed the state this year that one of its methods of verifying people's residences was insufficient. The Los Angeles Times reports this has caused headaches for thousands of people (including the article's author) who had received a new license that was supposed to be Real ID-compliant.

The TSA says every state has made some progress on tightening the documentation of people's IDs. But to be sure a traveler has a Real ID that will pass muster at a TSA checkpoint, the agency says Real ID-compliant IDs have a red star on the top of the card.

The REAL ID Act -- which was passed by Congress in 2005 after recommendations issued by the 9/11 Commission -- lays out minimum standards for state-issued driver's licenses and identification cards. The aim was to reduce identity fraud with forms of ID that are now required to fly or enter federal buildings. Besides REAL ID-compliant licenses or passports, the TSA will also accept federal government-issued IDs, known as Personal Identify Verification (PIV) cards, and U.S. military IDs.

Virginia began issuing the new form of Real ID-compliant licenses last year. Maryland's Motor Vehicle Administration (MVA) says it's been issuing Real ID-compliant driver's licenses since 2011, and the District of Columbia's Department of Motor Vehicles (DMV) started rolling them out in 2014.