'Historic mistake'

"This agreement is a historic mistake for the world," Prime Minister Benjamin Netanyahu said in a first reaction to the agreement. "Far-reaching concessions have been made in all areas that were supposed to prevent Iran from obtaining nuclear weapons capability. In addition, Iran will receive hundreds of billions of dollars with which it can fuel its terror machine."

And Naftali Bennett, Israel’s Education Minister, was quick to publish a hard-line tweet:

Iran has always maintained that its nuclear program is for peaceful purposes. Israel and much of the Western world suspect that Iran has been and is trying to develop nuclear weapons. Since 2011, the United States and Europe have imposed crippling economic sanctions on Iran to pressure Tehran into opening its nuclear facilities to foreign inspectors.

Under the terms of the agreement now reached, Iran will be allowed to continue research and development of centrifuges for the next 10 years. An arms embargo in place on Iran would continue for an additional five years.

Azriel Bermant, a research fellow at the Institute for National Security Studies, said the agreement could lengthen "breakout time" - the time needed to have an operable weapon – to up to a year. Bermant said it was not clear whether restrictions on Iran’s nuclear program would remain in force after 10 years. He said allowing research in centrifuges to continue was "not a welcome development" because it would shorten the time Iran would need to create nuclear weapons. Bermant also doubted world powers would manage to re-impose economic sanctions should Iran violate the terms of an agreement.

"Maybe some sanctions will be snapped back, but I think there will be a lot of holes," Bermant told DW. "Certainly the US will be able to impose sanctions, but I think other countries will buckle, Russia in particular, and there may be other European countries unwilling to reimpose sanctions."

Reducing the threat

Israel-based Iran analyst Meir Javedanfar told DW that the terms of the Vienna agreement might actually be beneficial. "To have tough inspections on Iranian soil carried out by international inspectors is good for the state of Israel," he said.

Javedanfar said a good deal would ensure effective enforcement, guarantee inspector access to Iranian military sites, ensure full disclosure of Iran's past possible military nuclear development, and provide transparency on centrifuge research and uranium supply. He said Israeli leaders who hoped for a tougher deal on Iran were unrealistic.

"They expect the Iranians to capitulate on everything, to pack up their entire nuclear program, dismantle everything, so that there is not even one centrifuge," he said. "And that position of Israel may be too unreasonable and too inflexible, and that's where it hurt our legitimacy."

Netanyahu, meanwhile, has hinted that Israel could attack Iran unilaterally to counter any Iranian threat. "We did commit to preventing Iran from attaining nuclear weapons - and this commitment still stands," he said on Tuesday.

Opposition leader and Labor Party chairman Isaac Herzog has accused Netanyahu of clumsy diplomacy that led to Israel's exclusion from negotiations. "The fact that there is no international attention to [Netanyahu's] claims and comments on the agreement in recent months is proof that his behavior and tactics failed," Herzog wrote on his Facebook page.

Lobbying the US?

In March, Netanyahu railed in the US Congress against the developing accord with Iran. He spoke at the invitation of Republican House Speaker John Boehner, in a move seen as a snub to US President Barack Obama.

Israeli leaders will now press to prevent Congress from ratifying the deal, which will once again pit Netanyahu against Obama.

Labor legislator Shelly Yechimovich, a member of the Knesset Foreign Affairs and Defense Committee, called on Tuesday for her party to avoid getting entangled in lobbying Congress.

"We need the United States in order to improve the bad agreement and maintain our deterrence via American aid," she tweeted.

In its opposition to the agreement with Iran, Jerusalem has an ally in Saudi Arabia, which is also fearful of a nuclear-armed Iran. Analyst Bermant said this could open the door for Israel to develop new regional alliances, "but at the end of the day if the US is determined to forge ahead with this agreement, then I'm not sure how much can actually be done to stop it."

On Monday, Netanyahu launched a Twitter account in Farsi. His account drew more than 1,500 followers in its first 24 hours, but many of the responses to his three posts were insults and calls of "Death to Israel."