Since Israel's founding in 1948, successive U.S. Presidents and many Members of Congress have demonstrated a commitment to Israel's security and to maintaining close U.S.-Israel defense, diplomatic, and economic cooperation. U.S. and Israeli leaders have developed close relations based on common perceptions of shared democratic values and religious affinities. U.S. policy makers often seek to determine how events and U.S. policy choices in the Middle East may affect Israel's security, and Congress provides active oversight of executive branch dealings with Israel and other actors in the region. Some Members of Congress and some analysts criticize what they perceive as U.S. support for Israel without sufficient scrutiny of its actions or their implications for U.S. interests. Israel is a leading recipient of U.S. foreign aid and is a frequent purchaser of major U.S. weapons systems. The United States and Israel maintain close security cooperation-predicated on a U.S. commitment and legal requirement to maintain Israel's "qualitative military edge" over other countries in its region. The two countries signed a free trade agreement in 1985, and the United States is Israel's largest trading partner. For more information, see CRS Report RL33222, U.S. Foreign Aid to Israel, by Jeremy M. Sharp. Israel has many regional security concerns. By criticizing the international interim agreement on Iran's nuclear program that went into effect in January 2014, Prime Minister Binyamin Netanyahu may seek to give Israel a voice in an ongoing negotiating process in which it does not directly participate. In addition to concerns over Iran, Israel's perceptions of security around its borders have changed since early 2011 as several surrounding Arab countries-including Egypt and Syria-have experienced political upheaval. Israel has shown particular concern about threats from Hezbollah, the Islamic State organization, and other nonstate groups in ungoverned or minimally governed areas in Syria, Lebanon, and Egypt's Sinai Peninsula, as well as from Hamas and other Palestinian terrorist groups in the Gaza Strip. Israel's political impasse with the Palestinians continues, and the most recent round of talks ended unsuccessfully in April 2014. Since the end of the 1967 Arab-Israeli War, Israel has militarily occupied the West Bank, with the Palestinian Authority exercising limited self-rule in some areas since 1995. Israeli settlement of that area, facilitated by successive Israeli governments, has resulted in a population of approximately 500,000 Israelis living in residential neighborhoods or settlements in the West Bank and East Jerusalem. These settlements are of disputed legality under international law. Israel considers all of Jerusalem to be the "eternal, undivided capital of Israel," but Palestinians claim a capital in East Jerusalem and some international actors advocate special political classification for the city or specific Muslim and Christian holy sites. Unrest and violence in Jerusalem have increased in the fall of 2014, with some ripple effects in the West Bank and in Arab communities in Israel. Although Israel withdrew its permanent military presence and its settlers from the Gaza Strip in 2005, it still controls most access points and legal commerce to and from Gaza. The territory presents complicated security and political challenges for Israel, in particular following a summer 2014 conflict involving Israel and Hamas.