Six months ago, 14-month-old Masa was just outside her family’s home when a bomb exploded nearby. Though physically unscathed, the emotional wounds are deep and apparent. Today, she is terrified of loud noises and screams anytime someone comes near her.

I met Masa and her parents, Aisha and Talal (not their real names), 28, two weeks ago in Akkar, one of the poorest districts in Lebanon, near the Syrian border. They and the hundreds of thousands of Syrian refugees like them decided to flee their country for the relative safety of Lebanon. Living in a garage with no proper flooring, Talal is struggling to make ends meet as a brick layer. He has only made $60 in the past three months, forcing him and his family to rely on $27 in monthly food vouchers from theWorld Food Program (WFP) to get by.

Their story is one that is repeated family-after-family throughout Lebanon and the region. With no political resolution in sight, the humanitarian needs of civilians caught in the crossfire have reached a boiling point. In just the first five months of 2013, more than one million Syrians fled to neighboring countries.

We know what they need, and that dire needs will persist for the long-term. There are dozens of organizations in the region that can meet those needs. Unfortunately, because we simply don’t have the funding, we in the humanitarian aid community are forced to say “No.”

UN High Commissioner for Refugees António Guterres recently said we have “not seen a refugee outflow escalate at such a frightening rate since the Rwandan genocide almost 20 years ago.” I was there in 1994, witnessing the horrible aftermath of the genocide, trying to help a deeply scarred population to cope with unimaginable loss.

Like Syria, it was a humanitarian crisis that was overwhelming in scale and complexity that will have a lasting impact on the population for generations. Unlike Syria, much of the actual death, destruction, and subsequent mass displacement did not play out on our television and computer screens in high definition every day. Perhaps most of us could say, “We didn’t know until it was too late.” When it comes to Syria, none of us can make excuses.

More than 100,000 people — mostly civilians — have been killed. Two million Syrians are already seeking refuge in neighboring countries, with some 6,000 more fleeing their war-shattered country every day. Whether living inside or outside the country, Syrians are living in an endless nightmare, and the international community is failing to come to their aid.

While hundreds of millions of dollars in military assistance has been provided to both sides of the conflict, humanitarian actors on the ground are struggling every day to meet people’s basic survival needs because we simply don’t have enough resources to do so. Last month, the UN launched its single largest ever appeal, more than $4 billion, in response to the Syrian crisis, but it remains vastly under-funded — which, in real terms, means that humanitarian organizations have to say “No” to people who desperately need assistance.

We are being forced to say “No” to millions of children like Masa.

In Lebanon, the challenges facing Syrian refugees are stifling. With no formal camps, the majority of Syrians are forced to rent what accommodation they can find. With work scarce and their savings dwindling, many fear eviction at a time when their stay in Lebanon is looking increasingly open-ended.

Now the only open neighboring border, Lebanon is receiving 3,000 refugees a day, and one in four people in the country is a refugee. This is having a broader negative impact. Many Syrians are settling into the poorest areas of Lebanon, like Akkar, creating an increased demand for jobs, resources, and basic commodities like food in communities that were already struggling to begin with. We are attempting to respond in Akkar, and some funding — namely from UNICEF and UNHCR — exists. But without more resources, we will only be able to offer a “quick fix” to Syrians as they arrive in Lebanon, and do virtually nothing for the Lebanese who are being impoverished as a result of the influx.

The harsh and obvious reality is that there is no end in sight to what has become a slow, bloody war of attrition.

We have a responsibility to the innocent who have been caught in the relentless barrage from all sides, their lives destroyed and lost, and to their host communities, also feeling the weight of the war every day. We have a responsibility to ensure they have places to live, food to put on the table, and a way to earn a living. We have a responsibility to ensure their children are able to continue their education so that their future is not defined by the failure of their leaders today.

Geopolitics and complexities are no excuse. Humanitarian aid dollars can still flow while negotiations and maneuvering take place in Geneva and elsewhere. And there are no embargoes against individual and institutional giving.

It’s simple. We cannot afford to say “No” to Masa any longer.