As I noted last night, the prospect of a merger between the Palestinian Authority and Hamas brought swift reactions from a number of lawmakers. Tommy Vietor, spokesman for the National Security Council, also had this to say: “As we have said before, the United States supports Palestinian reconciliation on terms which promote the cause of peace. Hamas, however, is a terrorist organization which targets civilians. To play a constructive role in achieving peace, any Palestinian government must accept the Quartet principles and renounce violence, abide by past agreements, and recognize Israel’s right to exist.”

But what if it doesn’t do that? The pact reportedly requires no such action by Hamas. I asked Vietor whether this meant that if a merger took place between Fatah and Hamas that the United States could not legally provide aid because Hamas did not as part of the pact renounce terror and recognize the state of Israel. He couldn’t provide anything beyond the initial statement. (The State Department tells me a statement will be forthcoming later today.)

But there really isn’t much wiggle room here. Since fiscal year 2005, annual foreign operations appropriations bills have included a prohibition on funding Hamas and the PLO, the relevant language being:

PROHIBITION TO HAMAS AND THE PALESTINE LIBERATION ORGANIZATION.— (1) None of the funds appropriated in titles III through VI of this Act may be obligated for salaries of personnel of the Palestinian Authority located in Gaza or may be obligated or expended for assistance to Hamas or any entity effectively controlled by Hamas or any power-sharing government of which Hamas is a member.

An expert on sanctions tells me the exception to this ban is limited: “In terms of U.S. aid, assistance may only be provided to a power-sharing government if the president certifies that such government, including all of its ministers or such equivalent, has publicly acknowledged the Jewish state of Israel’s right to exist; and committed itself and is adhering to all previous agreements and understandings with the United States Government, with the Government of Israel, and with the international community, including agreements and understandings pursuant to the Roadmap.” (The president alternatively can make a limited national security certification if it is in our national interest to provide assistance to the PA president’s security and administration, to help enforce border security and to assist the PA’s judiciary.)

Jonathan Schanzer of the Foundation for Defense of Democracies told me in a phone interview this morning, “There is precedent for this.” Schanzer explained that in April 2006 the United States cut off all aid to the PA after Hamas won elections. Only when Hamas staged a coup and Mahmoud Abbas set up a separate governing entity for the West Bank did we resume aid.

In the case of the current Fatah-Hamas merger, Schanzer argues that there is an immediate problem for the PA. Press reports suggest that Hamas is melding its operation into the PLO, the entity that does business and has offices in the United States. (In fact the Obama administration recently forked over more funds to upgrade these in anticipation of a peace agreement.) If this is correct, the offices would have to be closed and its representatives ejected from the country.

No doubt Hamas wanted to band together with the PA before any unilateral recognition of a Palestinian state occurred. And for Fatah, this is quite an achievement given that it has been trying to cajole Hamas into a partnership since the Yasser Arafat years. But with unity comes the distinct possibility, says Schanzer, that while the rest of the region is undergoing an Arab spring, the PA is about to enter a “diplomatic winter.”

UPDATE (12:45 p.m.): Sen. Marco Rubio (R-Fla.) sent this statement in response to the potential merger. “The announced agreement, if it becomes reality, would be a major setback for peace efforts in the Middle East and is not in the best interest of the Palestinian people. Participation in a Palestinian government of any organization, such as Hamas, that fails to renounce their calls for the destruction of Israel and the use of violence should prompt the withdrawal of our assistance. No American taxpayer money should fund a government that includes a terrorist organization dedicated to the murder of innocent civilians.”