The head of the World Evangelical Alliance and a group of retired U.S. armed forces generals have written to President Barack Obama urging him to provide aid for millions of refugees and to protect minority groups such as Christians suffering from the Syrian crisis.

Geoff Tunnicliffe, CEO and secretary general of the World Evangelical Alliance, released a letter Thursday sent on April 22 asking Obama to present a thorough strategy for U.S. engagement in resolving Syria's crisis.

"As Christian leaders and retired military personnel, we are writing to encourage your administration to develop and present to the American public a comprehensive strategy for US engagement in resolving the ongoing crisis in Syria," they say.

Those signing the letter include: former chairman Joint Chiefs, General Henry Shelton, Ret.; Admiral William Owens, Ret.;  Major General George Buskirk, Ret. and Major General Roger R. Blunt, Ret.

The letter notes that the crisis has led to the deaths of more than 140,000 people driving nine million have from their homes.

"Syria is a failed State that is already threatening its fragile neighbors and endangering world peace.

"As the world's most powerful nation, America's moral credibility is on the line.

"The U.S. must show leadership, specifically focusing on providing aid for the millions of refugees, protecting Christian minorities and other vulnerable populations from targeted violence," the Christian leaders and former generals write.

They say such U.S. leadership should work toward an effective and inclusive peace process that will end the war in Syria.

"These are daunting challenges, and we realize that there are no easy answers. But we ask you to redouble your efforts to meet these challenges."

'NATIONAL SECURITY AT STAKE'

The letter stressed that U.S. national security is at stake and that the Syrian conflict is destabilizing a region that was already volatile.

"We are well aware that the U.S. cannot involve itself in every conflict within other nations.

"But, we know that the world is too small to believe that what happens beyond U.S. borders has no impact on her citizens," states the letter.

It refers to "a recent spate of car bombs in Lebanon, increased cross-border attacks, and militarization of civilian populations is a clear indication that the conflict in Syria has already spread into neighboring countries."

Syria's neighbor Jordan faces the inescapable pressures that a large refugee population puts on limited natural resources, including increasingly problematic water shortages.

"The longer the violence continues, the greater the damage to the entire region."

The letters says that the total number of refugees fleeing into neighboring countries of Lebanon, Jordan, Turkey, and even Iraq is expected to reach 4 million in 2014.

This puts immense strain on the infrastructure and resources of the refugee receiving countries.

Syrian refugees currently make up 20 percent of Lebanon's population and in Iraq they are spilling into regions with strong Al-Qaeda affiliations.

"We are not naive idealists, blind to the political, economic and security challenges associated either with making peace or with providing aid on the scale that is needed," say the signers of the letter to the U.S. president.

"The United States must stand up for these especially vulnerable victims, by advocating that their representatives have a place at the negotiating table. It is a grave mistake to allow only the groups with guns a role in negotiating what a peace would entail."

Signers of the letter to President Obama:

Geoff Tunnicliffe, CEO and Secretary General of the World Evangelical Alliance

Former Chairman Joint Chiefs, General Henry Shelton, Ret
Admiral William Owens, Ret
Major General George Buskirk, Ret
Major General Roger R. Blunt, Ret
Major General Buford "Buff" Blount, Ret
Rear Admiral Stuart Platt, Ret
Brigadier General Pat Foote, Ret
Brigadier General Ted Vander Els, Ret
Brigadier General Michael Dunn, Ret