Earlier this month, the conscience of the entire world was shocked by the image of 3-year-old Aylan Kurdi's body washed up on a beach in Turkey. Like so many Syrians, Aylan and his family resorted to a dangerous and desperate journey to escape the horrific conflict in their homeland and seek refuge in the West. But while much of the world's attention has focused on how Europe is responding to the arrival of large numbers of refugees, we believe the memory of Aylan -- and thousands like him -- demands the United States, as a nation of immigrants, do more to facilitate the safe resettlement of Syrian refugees in our own country.

The Syrian conflict has led to the worst refugee crisis since World War II. More than half of Syria's 23 million people have been forced from their homes. Over 4 million Syrians are registered as refugees. Almost 2 million of these refugees are children, many of whom are under age 5. More than 10,000 Syrian children have already been killed.

We have visited refugee camps in Jordan and Turkey that house hundreds of thousands of Syrians. We have heard from men, women and children who have witnessed atrocities that, in the words of one refugee, would "make stones cry." As the Syrian civil war drags into its fifth year, the idea that these refugees can expect to go home in the foreseeable future appears increasingly unrealistic. The sheer numbers -- 1.9 million in Turkey, 1.2 million in Lebanon, 650,000 in Jordan -- strain the capacity of these front-line countries to provide basic services and threaten their stability as critical U.S. allies.

For these moral and strategic reasons, it is critical that the United States step up. That is why we wrote a letter, in which we were joined by 13 of our Senate colleagues, to President Barack Obama this spring calling on him to increase the number of Syrian refugees the United States accepts for resettlement. At the time we sent that letter, only about 700 Syrians had been resettled since 2011.

To the administration's credit, today almost 1,500 refugees have been accepted, and the latest news that the administration has committed to accepting at least 10,000 refugees next year is a positive step forward.

Meanwhile, for all the focus on Europe's struggles, its leaders are increasingly stepping up. German Chancellor Angela Merkel, whose country anticipates accepting 800,000 refugees by the end of the year, recently declared that, "As a strong, economically healthy country we have the strength to do what is necessary." British Prime Minister David Cameron has announced plans to take in 20,000 Syrians over the next five years. And Pope Francis has just issued a call to all Catholic communities in Europe to take in refugee families.

Yet while Europe is clearly stepping up its efforts, and the United States and our nonprofits remain significant contributors of humanitarian assistance in this crisis, we believe America should step up its refugee resettlement efforts. We therefore reiterate the call we made in our letter for the United States to continue its longstanding tradition of accepting 50% of refugees -- which would mean about 65,000 Syrians -- referred for resettlement by the U.N. High Commissioner for Refugees. This call is supported by a wide array of organizations with expertise in refugee issues, including the U.S. Conference of Catholic Bishops, Lutheran Immigration and Refugee Service, and the Episcopal Migration Ministries. To put that number in perspective, our country accepted nearly 125,000 Vietnamese refugees and nearly 90,000 Hmong for resettlement in the aftermath of the Vietnam War, and years later, they are a vital part of many of our communities.

We know that some have raised concerns about the security implications of accepting more refugees for resettlement. It is important to note that refugees are the most carefully vetted of all travelers to the United States, with extensive biometric, biographic, intelligence and law enforcement checks involving numerous agencies. We must continue to carefully screen refugee applicants for national security and terrorism concerns, but we must also devote sufficient resources and staff to ensure that this process does not hinder resettlement for legitimate refugees, many of whom are living in difficult, even life-threatening, situations.

Aylan Kurdi's tragic death galvanized the world to act, and it is within our nation's power to help ensure that more do not suffer the same fate. It is time for America to lead by example and join other countries in working to address the worst refugee crisis of our time.