Tens of millions of advertising dollars have been spent by conservatives and pro-Israel groups that want to kill the Iran deal.

Their efforts are likely to fail. It looks as if President Barack Obama will rally enough Senate Democrats to sustain his veto should legislators vote down the agreement.

But here’s what is so disturbing about the kill-the-deal campaign: It harms America’s security and Israel’s. It muddies the debate, and often whips up hysteria, like the video put out by the foundation of John Bolton, the former U.S. ambassador to the United Nations, which shows an American family being incinerated by an Iranian bomb.

If the critics (including Israeli leaders) really want to offset the deal’s weak points, they should pursue a different course.

First, they need to be honest about the consequences of scuttling the accord. Right now, Israeli Prime Minister Benjamin Netanyahu, along with conservative lobbying groups, claims the goal of rejecting the current accord is to renegotiate the agreement. This is not in the cards.

Anyone who believes otherwise should listen to Brent Scowcroft, the brilliant national security adviser to Presidents Gerald Ford and George H.W. Bush. “There is no credible alternative were Congress to prevent U.S. participation in the nuclear deal,” Scowcroft wrote last week in the Washington Post. “If we walk away, we walk away alone. We would lose all leverage over Iran’s nuclear activities. The international sanctions regime would dissolve.”

Were the deal to collapse, none of its 10- to 15-year restrictions on Iran’s program would come into play. Tehran would be free to pursue its nuclear program, build more advanced centrifuges, accumulate more highly enriched uranium, and restart its Arak plutonium reactor. The ayatollahs would be headed for “breakout capacity” (the accumulation of enough fissile material to make a bomb).

At that point, war hawks would be agitating for bombing Iranian facilities. But as Scowcroft notes, “no member of Congress should be under the illusion that another U.S. invasion of the Middle East would be helpful.”

Even if the United States joined Israel in striking Iranian nuclear targets, security experts estimate that this would set Iran’s program back only three to five years. If Washington undertook such a course after abandoning the Iran deal without testing its implementation, it would have no Western allies.

Hawks who dismiss such dangers should pay attention to recent leaks in the Israeli press about how Israel backed off plans to attack Iranian nuclear sites in 2011 after top security officials in Netanyahu’s cabinet got cold feet. Apparently, they feared large-scale civilian casualties if Tehran unleashed its Lebanese Hezbollah proxies, with their thousands of long-range missiles aimed at Israeli cities.

So despite Netanyahu’s rhetoric, Israeli leaders privately understand that a strike to prevent an Iranian bomb must come only as a last resort. Yet to abandon the Iran deal before it gets off the ground would put the United States and Israel on course for such a strike and at odds with the Europeans, Russians, and Chinese, who were all involved in negotiating the deal.

This brings us to the second point: If the critics of the deal really wanted to strengthen it, they would be pressing the administration to offset its weaknesses, not trying to kill it. “The question of whether the deal is good or bad depends on what we will do from now on,” I was told by Ami Ayalon, the former head of Israel’s domestic intelligence service.

Yes, indeed.

The critics are correct to worry about weaknesses in the verification provisions of the accord. Just about everyone expects Iran to cheat, so the question is how to buttress verification beyond the terms of the deal.

Ayalon said, “Intelligence-sharing is key.” He believes U.S., Israeli, and European intelligence agencies should “cooperate and share our resources on a daily basis. This is the way to provide what the deal is lacking.”

Others stress the need for close cooperation with, and providing additional resources for, the International Atomic Energy Agency, the U.N. atomic watchdog that will carry out inspections. (By the way, the controversial claim that the IAEA will let Iran take soil samples for inspection is still unverified and applies to only one Iranian site that was vacated a decade ago.)

There are plenty of other useful suggestions being put forward by U.S. and Israeli experts on how to supplement the deal — without scuttling it. These ideas apply to worries about what will happen after key provisions of the accord expire in 10 to 15 years, when Iran will be free to build advanced centrifuges and increase its supply of enriched uranium.

Some have proposed that Obama should rule out, now, Iran’s producing highly enriched uranium after the 10- to 15-year period, since there is no peaceful reason for it to do so. Others argue that the president should clarify that an Iranian sprint to a bomb in the future would trigger a U.S. strike.

Plenty of productive critics argue, rightly, that this deal requires Obama to take a tougher stand against Iranian aggression in the region, lest Tehran think the accord gives it a free pass to misbehave.

The point here is that there is ample room for strengthening the deal if critics are concerned about Israeli security rather than election sound bites. “To kill the deal is to kill American leadership in the region and to do a great damage to Israel’s position,” said Ayalon. Amen.

Trudy Rubin is a columnist for the Philadelphia Inquirer.