The story has been covered extensively in Germany and even in Israel, but it seems to have largely escaped notice in the United States: Israel has acquired a fleet of advanced German submarines that—Prime Minister Netanyahu has signaled—carry nuclear weapons pointed at Iran. The Obama administration’s pretense that it knows nothing about any nuclear weapons in Israel makes intelligent discussion about the dangers of nuclear weapons in the Middle East all but impossible. It has also vastly diminished respect for America’s broader worldwide effort to control the spread of nuclear weapons.

On January 12 of this year, the Rahav, the fifth of six German-built submarines scheduled for delivery, arrived at its base in Haifa. It’s an advanced diesel-electric boat that is equipped with air-independent propulsion—that is, it has its own oxygen supply and can stay beneath the surface for weeks, and do so more quietly than a nuclear-powered submarine. Its four extra-large torpedo tubes are sized—by numerous accounts—to fire Israeli long-range nuclear-tipped cruise missiles.

The strategic submarine procurement process started in the early 1990s, around the time of the first Gulf war. Germany’s position vis-à-vis Israel became especially awkward when it came to light that German firms had helped Saddam with his poison gas and missiles, some of which landed in Israel. Germany quickly agreed to pay for the first two submarines, a contribution that was cast as continued reparation for the World War II murder of millions of Jews.

Once the submarines took up their stations, the Israelis did not hide their mission. A 2011 Israeli Ynetnews story described an interview with the submarine fleet’s commander under the headline, “Doomsday weapon: Israel’s submarines.” A related Ynetnews story included the following:

Foreign reports suggest that the German subs serve as Israel's "second strike" power and aim to retain its nuclear capabilities, even in cases of an attack on the country. This supposedly serves to deter Iran or any future enemy which has the ability to destroy Israel.

The subject has been aired in the German press. A 2012 series in Der Spiegel reported the cruise missiles could reach Iran with a 200-kilogram warhead, a weight that permits a formidable nuclear yield. The German government kept mum.

Any shred of doubt about Israel’s possession of nuclear weapons, and about the presence of long-range nuclear missiles on the German-supplied submarines, got erased at last month's ceremony celebrating the Rahav’s arrival. The official speeches demonstrated that Israel’s nuclear weapons are no longer weapons of last resort, kept out of sight and only used in extremis; they are now integrated into its overall strategy. Prime Minister Netanyahu said the “submarine fleet is used first and foremost to deter our enemies who strive to extinguish us…They must know that Israel is capable of hitting back hard against anyone who seeks to hurt us." There is little doubt who “they” are. The Israeli leadership’s fixation with the threat of nuclear weapons in Iran’s hands has filled the news for years.

For the deterrent to work, Iran has to be aware of it, ergo the invulnerability of the undersea nuclear force has to be publicized, even flaunted. Leaving out the word “nuclear” doesn’t detract from the usefulness of the warning, while—such is human psychology—allowing Israel’s suppliers and supporters to maintain their pretense of ignorance. Had Netanyahu blurted out the truth, Germany would not have been able politically to continue to supply the submarines.

The US government, which has to be aware of the submarine’s nuclear role, has remained silent. The United States has consistently shielded Israel’s nuclear force from criticism in international arenas, squelching any effort to raise the subject; the taboo on discussing Israeli nuclear weapons apparently extends to the inner reaches of the US government. While the United States proclaims the Non-Proliferation Treaty (NPT) as the “cornerstone” of its nonproliferation policy and claims “unwavering” support for a Middle East nuclear weapon-free zone, America’s real policy is different: It aims to protect Israel’s monopoly on nuclear force in the area. That hypocrisy is not lost on the rest of the world, most of which takes a cynical view of US motives in pursuing nonproliferation.

This US policy carries a very real risk: As one of the four NPT holdouts (the others being India, North Korea, and Pakistan), Israel is also one of the countries most likely to use nuclear weapons against an adversary. All four of these non-signatories are involved in bitter disputes. While they all speak of using their weapons for deterrence, they do not rule out use of the weapons in response to non-nuclear provocation. Israel describes its sea-based nuclear missiles (omitting “nuclear,” of course) as a secure second-strike force. But a “second-strike” force in a tiny country that can be effectively eliminated by one nuclear weapon is bound to be an especially forward-leaning one. It makes for a dangerous state of affairs.

The essential first step in dealing with this danger—discussing it—is for the US government to acknowledge Israel’s nuclear weapons. Ending the pretense would lance the hypocrisy that so gravely undermines US efforts to control the spread of nuclear weapons and their means of delivery.