Guor Maker has led a remarkable life. He survived slavery and a brutal civil war in Sudan that claimed 28 members of his family, fled to a better life in America, graduated from college, and competed in two Olympics as a marathon runner. He even served as flag-bearer for South Sudan's first-ever Olympic team in the Rio Games. Today, he wears the flag of his new country and serves it in an even more important role, as an airman in the United States Air Force. In an era where old debates over immigration are resurfacing, Maker's only-in-America story is a reminder of how important immigrants are to this nation--and how much they sacrifice to serve and defend their new home.

Few Americans realize that 65,000 immigrants serve in the US military today. That number includes some 18,700 troops who hold green cards (in other words, legal permanent residents who are not yet naturalized citizens). According to the Pentagon, about 5,000 such residents enlist each year.

Since late 2001 when President George W. Bush implemented a new naturalization process for immigrant servicemembers, more than 109,300 US troops have been naturalized, according to the most up-to-date statistics from the US Citizenship and Immigration Services (USCIS). More than 11,000 of those military personnel became citizens during naturalization ceremonies in war zones such as Afghanistan and Iraq; in hot spots such as Jordan and Libya; in front-line posts such as Bahrain, Guantanamo Bay, Djibouti, Kenya, Korea, Kuwait, Qatar, Turkey, and the United Arab Emirates.

Immigrant military personnel are eligible for naturalization if they have "served honorably in the US Armed Forces for at least one year, obtained lawful permanent resident status and filed an application while still in the service or within six months of separation," USCIS explains.

Military service as a pathway to citizenship is not a new phenomenon. If anything, America's military was more immigrant-dependent in the past than it is today.