Two decades after the monstrous genocide in Rwanda, we find ourselves asking if history is about to repeat itself in the Central African Republic.

When 800,000 people were murdered in 100 days in Rwanda, the world dragged its feet to respond. From early on, the U.S. knew enough to save lives, but—opportunity after opportunity—it declined. The same is unquestionably true of the UN and for dozens of world leaders and allies who failed to act. When it was over, those leaders spoke the words that should have been on all of our lips from day one: “never again.”

Today, just as we are observing the 20-year commemoration of Rwanda’s genocide, that promise at last took one important step toward fulfillment.

To the north and west of Rwanda lies another landlocked African nation, where mass atrocities are constant, and the threat of genocide grows more real by the day. In the Central African Republic, an explosion of violence between Christian and Muslim militias has led to thousands of civilian murders.

As it was described by UN Secretary-General Ban Ki-moon, who visited CAR this past weekend, the nation has just in the past year “suffered the collapse of the state… and gruesome mass killing that has instilled widespread terror and sparked an exodus,” adding "The international community failed the people of Rwanda 20 years ago. And we are at risk of not doing enough for the people of the CAR today.”

Any one of these concerns would have been enough to spark global intervention. Together they have catalyzed the UN Security Council—with strong leadership from U.S. Ambassador Samantha PowerSamantha PowerUS to vote against UN resolution condemning Cuba embargo Former AG Lynch to meet with House, Senate Russia investigators The Memo: Tillerson flap puts spotlight on Trump's foreign policy moves MORE—to send 11,800 peacekeepers to CAR, under a mandate to protect civilians, restore rule of law, promote a political process and prevent, investigate, and report on human rights abuses. 

In approving this mission, which will take five months to fully transition from an African Union to UN operation, the UN Security Council and its members have done right by the memory of Rwanda. And while the UN’s action is by absolutely no means a catchall to addressing the world’s atrocities—for example, Syria—the CAR response nonetheless can profoundly change the lives of civilians, millions of whom are facing humanitarian disaster.

Still, our obligation does not end there. While approving this mission gives rise to hope that violence can be halted in CAR, to truly back this effort, the U.S. must also fund its part.

When President Obama submitted his FY 2015 budget request to Congress this year, he wisely anticipated needs in places like CAR, creating a “Peacekeeping Response Mechanism” to pay for the U.S. share of a potential mission. Now, the ball is in Congress’ court to see if the U.S. will follow his lead, and set aside such funding to pay new bills for a CAR mission next year.

As it stands, the U.S. is already in the red on its UN peacekeeping dues. The current FY’14 budget underfunds UN peacekeeping by a debilitating 12 percent. It provides no funding for the UN mission in Mali – a mission the U.S. specifically asked for in the Security Council, and which Republicans and Democrats hailed. 

If we fail CAR in the same way we have failed Mali—if we continue to make promises we cannot keep—the U.S. will show without doubt that little has been learned from the horrors of Rwanda. 

Addressing atrocity through the UN means that the U.S. does not have to take on these crises all on its own. In fact, our UN partners will foot roughly three quarters of the bill. What’s more, a U.S. GAO study has shown that sending UN peacekeepers to fulfill such dangerous missions—the missions we've asked for—is one-eighth the cost of the U.S. going it alone.  In addition, while peacekeeping is not a panacea, it can play a valuable role in efforts to stabilize countries wracked by conflict and protect vulnerable populations. For example, a 2013 study found that deploying several thousand UN peacekeepers “dramatically reduces civilian killings.” 

Fortunately there are some in Congress who have already begun to show support. Under leadership from Reps. Eliot Engel (D-N.Y.) and Karen BassKaren Ruth BassSessions grilled by lawmakers from both parties Niger tragedy underscores the need for a coherent Africa strategy, answers Congress must act on public health and community as the fiscal cliff approaches MORE (D-Calif.), a number of representatives on the House Foreign Affairs Committee have gone on record requesting not only that funds be set aside in the FY’15 budget for a mission in CAR, but also that the U.S. fully fund its peacekeeping commitments.

What’s more, U.S. Sens. Chris CoonsChristopher (Chris) Andrew CoonsA simple way to make America even greater is fixing our patent system Ensuring that defense agencies will have access to a community of entrepreneurs and innovators McConnell: 'I don't hear much pressure' to pass bill protecting Mueller from Trump MORE (D-Del.), Bob MenendezRobert (Bob) MenendezSenate ethics panel resumes Menendez probe after judge declares mistrial Judge declares mistrial in Menendez bribery case Menendez jury deadlocked, ordered to keep trying MORE (D-N.J.), and Jeff FlakeJeffrey (Jeff) Lane FlakeSpokesman: Flake’s vote on tax reform will have nothing to do with Trump Trump slams Flake over hot-mic comments: Senator's career is 'toast' Bannon: McConnell 'picking up his game' because of our 'insurgent movement' MORE (R-Ariz.) this week introduced a resolution honoring the memory of those lost in Rwanda, affirming that it is in the national interest of the United States to prevent and mitigate acts of genocide, and condemning ongoing atrocities in the Central African Republic.

Now it’s up to their colleagues to follow suit and pass a budget that will back up the Security Council’s decisive action.

We can never erase the memory of Rwanda, and what’s more it would be profoundly irresponsible to do so. What we can do is stop atrocities that are being committed in CAR and work to prevent them from ever happening again. Today’s action in the UN Security Council was the right step in that direction, and the Administration is to be commended for making it happen. Now the message must reach Congress: Let’s show the world we will follow through on our commitments with full funding for UN peacekeeping. 

Yeo is executive director of the Better World Campaign, a nonpartisan organization that works to strengthen the relationship between the United States and the United Nations.