Late last year, I visited the headquarters of a militant Islamist rebel militia called Suqour al-Sham in northern Syria.

Dozens of bearded young men were milling about an open courtyard, checking their guns, washing up, or eating. But, to my surprise, I also noticed a gaggle of clean-shaven youths who were secular in appearance. When I asked one of them why he had joined with Islamist militants to battle the regime, he replied:

“We want to fight (President Bashar) al-Assad, and only the salafis have the money and guns to do it.”

This scene, in a nutshell, explains why U.S. efforts to convene a Syria peace conference next month in Geneva are likely to go nowhere — and why the jihadi threat from Syria is growing. The hard-line Islamists have the money and guns to attract young fighters, while the West has let Syrian moderates collapse.

Despite repeated promises, the Obama administration has failed to support moderate rebel fighting groups, who are often short of bullets. The jihadis, on the other hand, are flush with cash from rich Arab donors, which enables them to attract more rebels to their militias.

“When the extremists need guns, they can call their financiers in Iraq, or South Asia, or the Gulf,” says Dan Layman, a spokesman for the Syrian Support Group, a U.S. group licensed to aid moderate Syrian forces. “When Assad needs more arms or funds, he can phone Russia or Iran. But when the moderate opposition needs supplies, they’ve confronted a confused U.S. administration that delayed for months before even dispatching MREs (meals ready to eat).”

The lack of a coherent strategy to back the moderates, says Layman, “is being far outpaced by the backers on the other side, who are playing this game to win.”

Of course, the administration’s hesitation is due in part to a well-placed fear that arms shipped to “moderate” rebel groups might be transferred to jihadis. And some Obama insiders may believe that U.S. interests are served by letting Assad and the jihadis duke it out.

But this kind of shortsighted thinking misses the bigger picture: Shortchanging moderate rebels (and they exist, though their numbers are shrinking) has not prevented the jihadis from getting guns. Moreover, allowing moderate Syrian rebel forces to collapse and jihadis to flourish creates a dangerous security threat for the entire Mideast — and for the West.

Assad’s survival is not threatened by the jihadis, who can’t take the big cities. Backed by Moscow and Tehran, he can withdraw to rule a rump Syria.

Meantime, if the moderate opposition collapses, the well-funded jihadis will be free to solidify their belt of control in eastern Syria and western Iraq — from which al-Qaida is already destabilizing Baghdad. Thousands of foreign jihadists from North Africa, Europe, and elsewhere, now fighting in Syria, will return to threaten their home countries.

Think Afghanistan of the 1990s redux. But this new jihadistan abuts Israel and borders the NATO nation of Turkey. And it seems to have access to unlimited funds.

Most of this cash, say experts who are following the money trail, is coming from private Arab donors in the Gulf, who want to promote Islamist upheavals worldwide.”A lot of the money is coming from just a few well-connected families and charitable organizations, particularly in Kuwait,” says William McCants, an expert on radical Islam at the Brookings Institution’s Saban Center. These radical groups, McCants says, have become skilled fund-raisers who pitch their cause on Twitter and YouTube.

So, rather than fixate on Geneva peace talks, the Obama team would be well-advised to revamp its strategy. For starters, it could pressure Gulf states, especially Kuwait, to clamp down on private donors to Syrian jihadis. This kind of pressure worked well after 9/11 in curbing private (Saudi) charities that were aiding jihadis worldwide.

Of course, Arab leaders are less likely to pay attention to U.S. pressure if the White House continues its costly dithering on Syria. The Saudis, Qataris, and Turks are reportedly trying, again, to organize and arm less radical Syrian militias. They won’t succeed unless Washington plays a leadership role.

And the administration — notably Secretary of State John Kerry — should recognize Geneva talks will be a joke without a credible moderate opposition.

As I saw so plainly at the rebel base in Syria, so long as the jihadis have the money, they will have the edge.