On January 17, Israel announced it was unilaterally ending its operation in Gaza. Israel's decision to undertake this unilateral cease fire followed the January 16 signing of a Memorandum of Understanding Between The United States and Israel Regarding Prevention of the Supply of Arms and Related Materiel to Terrorist Groups. The MOU, signed by Secretary of State Condoleezza Rice and Israel Foreign Minister Tzipi Livni in Washington D.C., provided Israel with the assurance that the United States will be a partner in preventing the flow of arms and military equipment to Hamas. Moreover, the MOU clearly reiterates the close and strong ties which are the basis of the special relationship between Israel and the United States.
Following these guarantees, Israel agreed to a one-week cease fire to enable negotiators to work out firm guidelines for ending Hamas' smuggling of weaponry into Gaza, and guarantees to stop Hamas rocket fire into Israel. By January 21, all Israel troops had left Gaza.
This cease fire is also intended to enable humanitarian assistance to flow into Gaza and reach those residents that require medical care and other aid.