"Germany is not paying their fair share," President Trump said at a press conference with NATO Secretary-General Jens Stoltenberg last week. "I have a great feeling for Germany, but they're not paying what they should be paying. We're paying for a big proportion of NATO, which is basically protecting Europe."

President Trump is right. Germany is not paying their fair share. In 2014 Germany and the rest of our NATO allies promised to raise their defense spending to 2 percent of gross domestic product by 2024. It is now 2019 and Germany still only spends 1.23 percent of its GDP on defense. By comparison, the United States spends 3.4 percent of GDP on defense.

And Germany is not alone. Not including the United States, NATO members spent only 1.48 percent of their GDP on defense in 2018 and just seven seven of NATO’s 29 member countries currently spend the recommended target of 2 percent of GDP.

With other NATO members defense budgets coming up short, the United States makes up 69 percent of all NATO defense spending despite U.S. GDP comprising less than half of NATO’s overall economy.

Congress can play a role in helping President Trump pressure our NATO allies to pay their fair share. That is why I introduced the Allied Burden Sharing Act last week, a bill that requires the Department of Defense to submit an extensive report that includes the common defense contributions of NATO countries and other defense partners including Australia, Japan, South Korea, New Zealand, Thailand, and the Philippines.

NATO and other mutual defense agreements have a purpose but the United States cannot and should not bear the greatest brunt of the financial burden in global alliances and defense partnerships. The information included in this report would be instrumental in informing lawmakers on the return on investment we receive in exchange for our contributions and commitments.

For security alliances and partnerships to be maximally effective, all parties must pull their weight.