Mark P. Lagon is president of Freedom House and a former U.S. ambassador at large for human trafficking from 2007 to 2009. Laila Mickelwait is director of abolition at the advocacy group Exodus Cry.

The International Labor Organization reported in 2014 that forced commercial sexual exploitation generates a startling $99 billion per year. Every day, millions of women and girls around the globe are being coerced to have sex for the financial gain of the pimps and traffickers who abuse and exploit them.

Whenever strategies for the elimination of sex trafficking are discussed, one theme consistently emerges: the importance of prevention through demand reduction. It seems like a no-brainer that reducing demand for commercial sex will reduce the exploitation of women and girls in the commercial sex industry. When a country allows for the legal purchase of sex, demand increases, as does the supply of women and girls needed to meet that demand. The reverse is also true: When countries prohibit the purchase of sex, fewer men buy, and fewer women and girls are trafficked. Legislation aimed at curbing demand for commercial sex can prevent sex trafficking.

In 2004, the State Department noted that, “where prostitution is legalized or tolerated, there is a greater demand for human trafficking victims and nearly always an increase in the number of women and children trafficked into commercial sex slavery.” This view has been shared by Republican and Democratic administrations. Last year, the State Department’s Office to Monitor and Combat Trafficking in Persons reiterated: “If there were no demand for commercial sex, sex trafficking would not exist in the form it does today. This reality underscores the need for continued strong efforts to enact policies and promote cultural norms that disallow paying for sex.”

So the State Department continues to talk the talk, but unfortunately it is unwilling to walk the walk. Year after year, the department sidesteps the most critical aspect of determining whether nations are truly “making serious and sustained efforts to reduce the demand for commercial sex,” as the Trafficking Victims Protection Act mandates. Punishing those who seek to purchase commercial sex is the one proven indicator of whether a country is making efforts to reduce demand. But it seems the department doesn’t want to ruffle feathers by turning words into action.

Take Spain, where purchasing sex is legal and most detected trafficking cases are for the purpose of prostitution. The U.N. Office on Drugs and Crime noted that 39 percent of the male population in Spain admitted to purchasing sex at least once. According to a 2007 Spanish government study, sex is purchased between 900,000 and 1.5 million times a day in a nation of 47 million. Cities attract and cater to tourists for whom purchasing sex is an expected part of the nightlife. Club Paradise in La Jonquera, one of the largest brothels in Europe, boasts of having more than “200 girls” who work in 101 rooms to cater to the desires of men who are free to buy sex without consequence.

According to the State Department’s global Trafficking in Persons (TIP) report, there may be as many as 400,000 women being prostituted in Spain, and up to 90 percent of these women are trafficked and coerced into prostitution by organized crime — meaning up to 360,000 women are victimized. Yet for the past 14 years, Spain has received a “Tier 1” ranking in the report, meaning the country is in full compliance with minimum standards set forth to eliminate trafficking. There has been no mention of the fact that the legality of purchasing sex in Spain is a magnet for human trafficking. In the 2014 TIP report , the department even gives Spain credit for prevention of trafficking: “the government [of Spain] continued prevention efforts through a variety of public awareness campaigns involving flyers, banners, exhibits, and other displays.” No amount of flyers should warrant giving a nation that allows men to buy sex with impunity a “passing” grade on prevention of human trafficking.

Enough is enough. Any national government having the authority to criminalize the purchase of commercial sex should do so. It’s time for Congress to pass pending legislation sponsored by Rep. Randy Hultgren (R-Ill.) that would update the Trafficking Victims Protection Act to require future TIP reports to assess sex-purchase laws when determining whether nations are making serious efforts to reduce demand for commercial sex.

The grades that the United States gives in its global TIP report matter. They can sometimes cause diplomatic indigestion, but they have propelled nations to improve their conduct. They would be a stronger tool if they took seriously the need for nations to hold to account the men who would buy women and girls for sex. It is high time to stop saying “boys will be boys” and recognize that abolishing sex trafficking requires placing the stigma on the purchaser rather than the commodified women and girls they buy.