When President Barack Obama leaves the White House next January, people around the world will debate his legacy for years to come. But for the children of South Sudan, his legacy is clear: He has failed them.

Last week, the White House announced which countries will receive waivers to the prohibition on U.S. security assistance under the Child Soldiers Prevention Act (CSPA). And this year, as with every other year, South Sudan was included in that list. With this announcement, the Obama administration has squandered its last chance to hold the corrupt, malignant South Sudanese leadership accountable for its crimes, depriving the boys and girls who have suffered at its hands of any justice.

The CSPA, passed in 2008, prohibits the U.S. government from furnishing security assistance or selling arms to any government that has been identified as recruiting children into its armed forces or armed groups that it supports. To that end, every year the State Department releases a report in May listing countries whose governments have been found to recruit or use child soldiers. Theoretically, the United States would sanction those countries under the law.

But the law comes with a significant loophole: The president can waive CSPA sanctions if he determines that such a waiver is “in the national interest of the United States.” That’s exactly what Obama did last week.

Since 2010, the United States has furnished more than $1 billion in security assistance to governments listed by the CSPA that should have been withheld. According to research from the Stimson Center, only 4 percent of military aid that should have been kept out of the hands of governments that recruit and exploit children has actually been withheld. Obama’s liberal use of the waiver has not only stripped the law of meaning, but has also relieved these militaries of an important incentive for professionalizing their armed forces by ending the use of child recruitment.

South Sudan is among the more tragic examples of how the United States has failed to uphold the CSPA and protect children from exploitation and harm.

The fledgling country is among the most corrupt in the world. Local power brokers—including President Salva Kiir and former Vice President Riek Machar, the leaders of rival factions now engaged in a 3-year-old civil war—have used their positions to plunder the country of its wealth, while subjecting their citizens to one of the most hellish humanitarian disasters on earth.

Among their many crimes, South Sudan’s security forces have been known to recruit child soldiers since the country gained independence in 2011, but recruitment increased rapidly once hostilities began between the government’s Sudan People’s Liberation Army (SPLA) and various rebel groups associated with the opposition in December 2013.

According to the United Nations, coercion—including threats of violence against family members and attacks on villages—is widely employed to force children into combat. In 2015 alone, recruitment efforts affected more than 2,500 children. The SPLA and other government-supported armed groups were responsible for the majority of those cases. And despite appearing on the CSPA list since 2012, the U.S. government has withheld only $1.2 million of security assistance, while providing $99 million.

In previous years the Obama administration has justified its decision to provide the aid as part of an effort to support a cease-fire between warring parties. But these arguments do not hold up, especially since the resumption of hostilities in July. According to UNICEF, at least 650 children have been recruited this year alone.

When UNICEF announced that new recruitment of children was taking place, the State Department quickly issued a statement condemning South Sudan for such practices.

“The continued unlawful recruitment and use of children in armed conflict in South Sudan is unacceptable,” read the statement from department spokesperson John Kirby. “Eliminating the unlawful recruitment and use of child soldiers for armed groups in South Sudan is a leading priority of the United States. We remain committed to securing accountability for those who recruit and use children as soldiers.”

But as the recent waiver has shown, those were nothing but empty words.

The CSPA was created precisely for situations like South Sudan. The administration could have used this opportunity to help the citizens of South Sudan by upholding the prohibition and depriving the country’s leaders of what they already have too much of: weapons and military equipment.

The task now falls to the next administration to enforce its laws prohibiting the exploitation of children. U.S. military assistance to foreign governments like South Sudan must be contingent on effective steps to reform security institutions. Before even a single bullet is handed over to South Sudan, its government must adopt and apply strict rules eliminating the recruitment or use of child soldiers. Commanders who violate those rules must be held to account and disciplined. The United States can help reform South Sudan’s forces, but only if its government is willing to take the first step.

If the South Sudanese government is not willing to stop pressing kids into combat, then the United States would be better off walking away from military assistance. U.S. resources should be redirected toward grants to UNICEF or civil society organizations to provide emergency education and health services to help demobilize and rehabilitate child soldiers.

Cutting off military aid might not compel the government of South Sudan to change course, but at least the U.S. government won’t be complicit in putting guns in the hands of little boys and girls.

Geoffrey Duke is a peace activist with the South Sudan Action Network on Small Arms. He lives in Juba, South Sudan.