As Lebanese Prime Minister Saad Hariri makes the rounds in Washington today and tomorrow, he faces deep questions in Congress and in the Defense Department about the future of the U.S. military aid to the Lebanese Armed Forces.

Supporters of the funding, mostly at the State Department and the White House, argue that strengthening the Lebanese military is the best way to bolster Hariri against the mounting influence of both Syria and Hezbollah, the radical Shiite militant group, inside Lebanon. The Lebanese military, this faction argues, is the most representative of the country's civic institutions and continuing the funding can help convince Hariri that working with the U.S. is a beneficial and defensible strategy.

But many lawmakers and some at the Pentagon, including Secretary of Defense Robert Gates, are extremely skeptical that continuing to funnel large amounts of cash and supplies to the LAF is really a good way to approach the Lebanon problem. They are angry about statements Hariri has made about Syria's alleged transfer of long-range missiles to Hezbollah, and question whether the military aid to Lebanon is part of a coherent strategy.

"Threats that Lebanon now has huge missiles are similar to what they used to say about weapons of mass destruction in Iraq," Hariri reportedly said last month. "These are weapons that they did not find and they are still searching for."

But Hariri's reaction to the alleged arms transfers has given many inside the administration pause. There's also a concern he could let U.S. weapons slip into the hands of Hezbollah, although the track record of the LAF in that regard has been solid so far.

"The number one issue now is arms transfers from Syria to Hezbollah and this confounds our policy of supporting the Lebanese military," said Andrew Tabler, a fellow at the Washington Institute for Near East Policy. The Obama administration wants Hariri to use the state's instruments of power, such as the LAF, to confront Syria over the alleged arms transfers, but Hariri is in no position to confront Damascus.

Hariri has been careful not to upset Syrian President Bashar al-Assad, who is widely thought to have ordered the 2005 assassination of his father, former prime minister Rafiq al-Hariri.

"It would be hard for anyone not to take note that he visited Damascus before he visited Washington," said long-time Lebanon hand Firas Maksad, who said that Hariri is walking a very thin line as he tries to placate the United States and Syria at the same time.

Overall, the arms transfers are on balance a good idea, said Maksad. "We need to think about how we can strengthen our leverage in Beirut. At the end of the day, that's the only hope for a counterbalance to Hezbollah."

But lawmakers, always looking to pinch pennies, and Pentagon officials, who are most concerned about the Hezbollah-Israel tensions, aren't satisfied that strategic hedging is enough of a justification for continued military assistance like on the order of $500 million since 2006.

"The Defense Department has always asked the question: Why are we doing this, what are the objectives, what is the end state we are trying to achieve in Lebanon?," said Aram Nerguizian, visiting fellow at the Center for Strategic and International Studies. "It's an idea that is not linked to an end state. We like the process, but ultimately, what is it that the U.S. is trying to do in Lebanon? That's what hangs in the balance."

Mona Yacoubian , who just released a new report on the Syria-Lebanon situation for the U.S. Institute of Peace, said that there is growing concern inside the administration that the shift of power inside Lebanon toward Hezbollah suggests that it may not be wise to put more resources into the Lebanese military. She argues, however, that the best way to deal with Hezbollah is to help build and strengthen the Lebanese state.

Meanwhile, Hariri is faced to deal with the facts on the ground, which are clearly tipping toward a negative direction, she said.

"He's coming to Washington with a very difficult task. He's got to balance day-to-day concerns with the broader concerns of his ally, the U.S. If he moves to please us, he angers Syria, Hezbollah, and others. If he seems to mimic the U.S. position, he suffers at home. He's in a no-win situation."

The White House readout of Hariri's meeting with President Obama gave little inkling of these tensions, and said the meeting focused on Arab-Israel peace effort, the suspected transfer of Syrian weapons to Hezbollah, and Lebanon's role as rotating president of the U.N. Security Council, which is currently mulling over new sanctions against Iran. But the statement also pointed to President Obama's "determination to continue U.S. efforts to support and strengthen Lebanese institutions such as the Lebanese Armed Forces and the Internal Security Forces."

Privately, the White House was sending a much tougher message, however. Hariri brought so many officials into his bilateral with Obama, sources say, there was no way to speak frankly about subjects of real contention, like U.S. military support and Hariri's unhelpful statements regarding the alleged Hezbollah arms transfers. So Obama and Hariri had a separate, private meeting amongst themselves, where we hear the tough messages were really delivered.

Hariri also met with Gates, Assistant Secretary of State Jeffrey Feltman, and Middle East Special Envoy George Mitchell today. Feltman, who was the U.S. ambassador in Beirut at the time of Rafiq al-Hariri's assassination, released a statement citing Lebanon's role in promoting international security and "the key role of Lebanon in the long-term effort to build a lasting, comprehensive peace in the Middle East."

But Feltman didn't mention Lebanese military assistance, which will be at the top of lawmakers' agendas Tuesday.

"His meetings went very well today," David Schenker, director of the Arab politics program at the Washington Institute for Near East Policy, said of Hariri. "I don't think that's going to be the case when he goes to Capitol Hill tomorrow."

The administration has requested $100 million for the LAF in its Fiscal 2011 budget request.