Every president since Lyndon Johnson has reiterated the U.S. commitment to maintain Israel's qualitative military edge (QME). The principle behind this commitment is simple: Israel is a bastion of liberal, representative government in the Middle East and, as such, its survival is a vital U.S. national interest. To ensure the continued existence of this longtime U.S. ally in a sea of countries that reflexively call for its destruction, Israel must be able to defend itself militarily and deter aggression. While a coalition of Arab states can always outnumber Israeli forces in terms of troops, artillery, tanks, and combat aircraft, the United States can assure its survival if Israel is able to maintain qualitative military superiority, relying on more advanced weaponry, training, leadership, and tactics to deter or defeat its adversaries in the Middle East. But while maintenance of Israel's QME continues to be in the U.S. strategic interest, the shifting political and military dynamics in the Middle East demand a clearer definition of QME and mutual agreement between Washington and Jerusalem about how that QME can and should be maintained.
As the conventional weaponry and training of the other regional states has caught up to that of Israel, the Israeli government has relied increasingly on its unacknowledged nuclear capability to deter its potential adversaries, reducing the effect that U.S. regional arms sales have on Israel's QME. For Washington, arms sales are powerful political and military signals of the U.S. intention to stand by its allies, both Israeli and Arab. At the same time, the potential adversaries against whom QME must be maintained are changing. States such as Egypt and Saudi Arabia now pose less threat and even find themselves strategically aligned with Israel in their desire to contain and deter Iran's regional aims and the development of the Islamic Republic's own nuclear capacity.
Because the strategic bifurcation of the Middle East into Israel and a monolithic Arab bloc is no longer relevant, traditional assumptions regarding QME do not hold true anymore. For example, the sale of sophisticated conventional weaponry to Arab states no longer necessarily implies a corresponding reduction in Israel's QME. Instead, such a sale is a double-edged sword, reducing Israel's QME to the extent such Arab states continue to represent Israeli adversaries but increasing Israel's QME by increasing the military capability of states aligned with it in their desire to deter Iranian aggression. Any new concept of Israel's QME should consider this dynamic and both inoculate Israel against threats from its neighbors and also account for Israel's and the United States's mutual interest in ensuring that moderate Arab states retain sufficient capability to deter Iranian belligerence.