TEL AVIV -- In April, Obama administration national security adviser Susan Rice told Jeffrey Goldberg of The Atlantic that the Joint Comprehensive Plan of Action (JCPOA) entered into with the Islamic Republic of Iran in 2015 was “pragmatic and minimalist.”

“The aim,” Rice said, “was very simply to make a dangerous country substantially less dangerous.”

One year later, the Israeli national security establishment continues to debate the Iran deal’s merits. Although the debate no longer garners headlines, behind the scenes experts are divided over the reliability of the deal’s oversight mechanisms and whether, even if Iran were to scrupulously honor its obligations, the JCPOA would place the Shiite theocracy intolerably close to the production of nuclear weapons.

One aspect of the agreement, however, is subject to little dispute in Israel. By decoupling negotiations over its nuclear program from Iran’s funding of terrorism and export of Islamic revolution, most here concur, the agreement has fortified Iran’s short-term capacity to destabilize the region. The Joint Comprehensive Plan of Action was not comprehensive.

Although President Obama regularly maintained that the only serious choice the United States confronted was between war with Iran and the deal struck by his team, Israeli Prime Minister Benjamin Netanyahu argued for a third option.

A better deal, Netanyahu insisted in his controversial March 2015 address to Congress, would have forced Iran to make much deeper cuts in its nuclear infrastructure. It would have required Iran to cease its threats to annihilate Israel. And it would have compelled Iran to end its aggression throughout the Middle East—at the moment Supreme Leader Ayatollah Ali Khamenei is backing Islamists in Yemen, Iraq, Syria, Lebanon, and the Gaza Strip.

Of special concern to Israel is that under the cover of the JCPOA, Iran has continued to arm Hezbollah—Shiite Islamist militants headquartered in the south of Lebanon who constitute Israel’s largest conventional threat.

Since the 2006 Lebanon War, Hezbollah has increased tenfold its massive arsenal of rockets and missiles targeting Israel. This Iranian proxy now possesses more than 100,000 short-range rockets, some with advanced guidance systems recently shipped from Iran, and thousands of precision missiles that can strike all of Israel’s major cities and inflict significant damage on Israeli military bases. Hezbollah also boasts a considerable supply of anti-aircraft, anti-ship, and anti-tank missiles.

By basing its rockets and missiles in towns and villages throughout southern Lebanon, Hezbollah has ensured that effective Israel defensive measures will result in thousands of Lebanese civilian casualties and appalling damage to civilian infrastructure. “Both legally and morally,” notes international laws of war scholar Geoff Corn, “the cause of these tragic consequences will lie solely at the feet of Hezbollah.” Nevertheless, if recent history is a guide, the international community will absolve Hezbollah of guilt while heaping blame on Israel for the likely carnage in Lebanon.

So what is Hezbollah waiting for? Why hasn’t it already attacked Israel? Eran Lerman, who stepped down last year as deputy national security adviser to Netanyahu, told me that multiple factors are restraining Hezbollah—at least for now.

First, the high cost Hezbollah paid 10 years ago in the Second Lebanon War established “straightforward deterrence.” Although much of the media portrayed the 34-day military conflict as a draw (and Hezbollah leader Hassan Nasrallah hailed it as a “divine victory”), Hezbollah sustained heavy casualties and saw its rocket and missile arsenal severely degraded. A measure of the price Hezbollah paid is the quiet that has prevailed on Israel’s northern border for the last decade.

Second, Iran exercises “a derivative deterrence” over Hezbollah, according to Lerman, who is a fellow at the Begin-Sadat Center for Strategic Studies at Bar Ilan University and teaches at Shalem College in Jerusalem. Iran considers the Islamist militant group’s fearsome stock of rockets and missiles as essential to its ability to deter an Israeli strike on Iranian nuclear facilities. To deter Israel, Iran must rein in Hezbollah.

Third, Hezbollah is also derivatively deterred by the Syrian civil war. While thousands of Hezbollah combatants in Syria have gained invaluable battlefield experience with sophisticated weapons systems, Hezbollah has also incurred serious losses in the Syrian killing fields. The organization’s leaders know that their Sunni adversaries would leap at the opportunity to wipe out a Hezbollah fighting force weakened by war with Israel and, in the process, would exact brutal revenge on a thoroughly exposed Shiite civilian population in southern Lebanon.

These multiple levels of deterrence fall far short of ensuring that ordinary misunderstanding and miscalculation, Hezbollah’s Islamist fanaticism, and the tumult spread throughout the Gulf and the Levant by fighters loyal to Iran will not in the near term trigger an unintended, ruinous full-scale war between Israel and Hezbollah.

The unfolding of events seems to have vindicated Netanyahu’s warning that Obama’s top foreign policy priority would exacerbate regional instability. Because America’s Sunni Arab allies largely agree with Netanyahu’s assessment, the deal has also diminished American prestige in the Middle East.

This was a foreseeable consequence of Obama’s unconventional version of balance-of-power politics: Instead of strengthening American allies—Israel and friendly Arab states—to restrain a tenacious adversary, the president devoted enormous effort to striking an agreement with Iran that strengthened Washington’s principal regional adversary at the expense of America’s local allies. In the effort to strike a “pragmatic and minimalist” deal, the administration has, contrary to Susan Rice’s assertion, made Iran—in the short run, at least—more dangerous.