With so many flaws, the Vienna agreement on Iran’s nuclear-weapons program is generating considerable debate. But beyond the deal’s many deficiencies, broader implications ― almost entirely negative for the United States and its closest allies ― are still not well understood.

Consider just a few of the Vienna deal’s long-term effects. Some could well materialize before the end of Mr. Obama’s presidency, as states and terrorists try to take advantage of the White House’s palpable weakness and inattention. All will persist for decades unless unambiguously reversed by a new president in 2017.

First, the negotiations themselves, clearly long headed in the wrong direction, have fueled an already-nascent nuclear-arms race in the Middle East. Saudi Arabia already had contingency plans to buy nuclear weapons directly from Pakistan, or perhaps even for constructive possession. Now, Riyadh has launched its own domestic nuclear programs, for “peaceful purposes,” of course. Egypt, Turkey and Jordan have announced similar plans for indigenous nuclear programs and other regional states could follow.

Moreover, the nuclear proliferation implications extend well beyond the Middle East. Iran’s victory in Vienna, which paves its way to nuclear weapons, is also evidence to all other would-be nuclear states. Sadly, therefore, the odds are high that the number of nuclear weapons states will grow dramatically in the next decades.

Second, the Iran deal proves yet again that Mr. Obama gives little or no credence to Israel’s security concerns, much like the administration’s repeatedly failed efforts to force a settlement between Israel and the Palestinians that would endanger Israel’s self-defense capabilities. White House rhetoric notwithstanding, Israel is on the verge of being cast adrift by its closest ally.

Ironically, America’s Arab friends now see us as increasingly unreliable, cutting and running from a complicated, dangerous region, and leaving them adrift. They have already begun to conclude they need other strong friends, and will not be troubled or hesitant if some of those new friends, such as Russia and China, have heretofore been seen as supporters of Iran. Duplicity, double-dealing and contradictory commitments are hardly novel arrangements in the Middle East, and will not take long to develop here. The unifying theme in what may otherwise seem superficially confusing is the palpable decline of both American influence, and international peace and security.