American leaders have traditionally explained the foundations of the U.S.-Israel relationship by citing shared democratic values and the moral responsibility America bears to protect the small nation-state of the Jewish people. Although accurate and essential, this characterization is incomplete because it fails to capture a third, crucial aspect: the many ways in which Israel advances U.S. national interests.

Today, Israeli contributions to U.S. national interests cover a broad spectrum. Through joint training, exercises and exchanges on military doctrine, the United States has benefited in the areas of counter-terrorism, intelligence and experience in urban warfare. Increasingly, U.S. homeland security and military agencies are turning to Israeli technology to solve some of their most vexing technical and strategic problems.

This support includes advice and expertise on behavioral screening techniques for airport security and acquisition of an Israeli-produced tactical radar system to enhance force protection. Israel has been a world leader in the development of unmanned aerial systems, both for intelligence collection and combat, and it has shared with the U.S. military the technology, the doctrine and its experience regarding these systems. Israel is also a global pacesetter in armored vehicle protection, defense against short-range rockets, and the techniques and procedures of robotics, all of which it has shared with the United States.

In missile defense, the United States has a broad and multifaceted partnership with Israel. Israel's national missile defenses — which include the U.S. deployment in Israel of an advanced X-band radar system and the more than 100 American military personnel who man it — will be an integral part of a larger missile defense spanning Europe, the eastern Mediterranean and the Persian Gulf to help protect U.S. forces and allies.

Israeli-developed defense equipment, some of which benefited from generous U.S. aid, now used by the U.S. military include short-range unmanned aircraft systems that have seen service in Iraq and Afghanistan; targeting pods on hundreds of Air Force, Navy and Marine strike aircraft; a revolutionary helmet-mounted sight that is standard in nearly all frontline Air Force and Navy fighter aircraft; lifesaving armor installed in thousands of MRAP armored vehicles used in Iraq and Afghanistan; and a gun system for close-in defense of naval vessels against terrorist dinghies and small-boat swarms. Moreover, U.S. and Israeli companies are working together to produce Israel's Iron Dome — the world's first combat-proven counter-rocket system.

Counter-terrorism and intelligence cooperation is deep and extensive, with the United States and Israel working to advance their common interest in defeating the terrorism of Hamas, Hezbollah and Al Qaeda and its affiliate groups, and preventing nuclear proliferation in the region. There are joint Special Forces training and exercises and collaboration on shared targets.

This intimate relationship reinforces overall U.S. intelligence efforts by providing Washington with access to Israel's unique set of capabilities for information collection and assessments on key countries and issues in the region. Such was the case, for example, when Israel passed to the United States conclusive photographic evidence in 2007 that Syria, with North Korean assistance, had made enormous strides toward "going hot" with a plutonium-producing reactor.

On important issues, the two nations do sometimes differ, a phenomenon not unique to the U.S.-Israel relationship. Over the decades, there have been periodic policy flare-ups, some even bitter, on topics ranging from Israel's preventive action against Iraq's nuclear reactor to Israeli sales of weaponry and military technology to China. Some of the most contentious disputes have been about actions affecting the Middle East peace process. But more often have been instances of U.S.-Israel collaboration — most important, the Arab-Israel peace treaties that are the anchor of American national interests in the Middle East.

We do not deny that there are costs to the United States, in the Arab world and elsewhere, for its support of Israel, as there are costs to U.S. support of other beleaguered — and sometime imperfect — friends, including West Berlin in the Cold War, Kuwait in 1990-91 and Taiwan today.

But the long-standing U.S. commitment to Israel has not prevented development of close ties with Arab nations, which understand — however much they disagree with U.S. support for Israel — that they benefit from a good relationship with the United States on other issues. Nor has it made the Arab oil-exporting states any less conscious of their own economic and strategic interest in a reasonably stable flow of oil to world markets, or their eagerness to buy first-class military equipment from the United States or to enjoy the benefits of U.S. protection against Iranian or other aggression.

Would Saudi Arabia's policies toward the United States, for example, be markedly different if Washington entered into a sustained crisis with Israel over the Palestine issue? Would Riyadh lower the price of oil? Would it stop hedging its regional bets concerning U.S. attempts to coerce Iran into freezing its nuclear weapons programs? Would it regard current U.S. policy toward Afghanistan more positively? Would it view American democracy promotion in the Middle East more favorably? Would it be more inclined to reform its internal governmental processes to be more in line with U.S. preferences? No.

In sum, we believe that Israel's substantial contributions to U.S. interests are an underappreciated aspect of this relationship and deserve equal billing to shared values and historical responsibility as rationales for American support of Israel.

Robert D. Blackwill, deputy national security advisor for strategic planning in the George W. Bush administration, and Walter B. Slocombe, undersecretary of defense for policy in the Clinton administration, are authors of the new report "Israel: A Strategic Asset for the United States" (The Washington Institute for Near East Policy).