the former Soviet Union to Israel, and has assisted in their absorption into Israeli society. In addition, there has been immigration between the two countries, with many American Jews immigrating to Israel annually, while the United States is the top destination for Israelis emigrating abroad (yerida) permanently or for an extended stay. Corporate exchange Several regional America–Israel Chambers of Commerce exist to facilitate expansion by Israeli and American companies into each other's markets. American companies such as Motorola, IBM, Microsoft and Intel chose Israel to establish major R&D centers. Israel has more companies listed on the NASDAQ than any country outside North America. Strategic cooperation The US and Israel are engaged in extensive strategic, political and military cooperation. This cooperation is broad and includes American aid, intelligence sharing, and joint military exercises. American military aid to Israel comes in different forms, including grants, special project allocations, and loans. President Obama pledged to maintain Israel's "QME" over the other countries in the region. Memorandum of Understanding on security To address threats to security in the Middle East, including joint military exercises and readiness activities, cooperation in defense trade and access to maintenance facilities. The signing of the Memorandum of Understanding marked the beginning of close security cooperation and coordination between the American and Israeli governments. Comprehensive cooperation between Israel and the United States on security issues became official in 1981 when Israel's Defense Minister Ariel Sharon and American Secretary of Defense Caspar Weinberger signed a Memorandum of Understanding that recognized "the common bonds of friendship between the United States and Israel and builds on the mutual security relationship that exists between the two nations". The memorandum called for several measures. Missile defense program One facet of the US–Israel strategic relationship is the joint development of the Arrow Anti-Ballistic Missile Program, designed to intercept and destroy ballistic missiles. This development is funded by both Israel and the United States. The Arrow has also provided the US with the research and experience necessary to develop additional weapons systems. So far, the development cost has been between $2.4 and $3.6 billion, with the United States picking up 50 percent of the final costs. The US has notably provided funding for Israel's Iron Dome short-range missile defense system: from 2011 until 2022, the United States contributed a total of US$2.6 billion to the Iron Dome defense system. Counter-terrorism In April 1996, President Bill Clinton and