CBS News - The Senate on Thursday overwhelmingly passed�legislation that would impose new U.S. sanctions that would target Iran's ballistic missile program, human rights violations, and yet it would still comply with the Iranian nuclear deal.

Senators voted 98-2 in favor of the measure.

Bipartisan negotiations also led to the bill including expanded sanctions on Russia, in response to its intrusion into Ukraine, efforts to meddle in the 2016 election and its support for the Syrian regime.

Iran sanctions on ballistic missile program

The overarching part of the measure -- Countering Iran's Destabilizing Activities Act of 2017 -- would impose sanctions on any foreign person or foreign entity that does business with an entity already designated by the administration that has a connection to Iran's ballistic missile program. These sanctions, for example, could apply to any financial institution or any foreign company that provides key parts or components to Iran's missile program.

"It's a much more powerful sanctions measure than merely just designating Iranian entities that are involved in missile development," said Mark Dubowitz, CEO of the nonpartisan think tank Foundation for Defense of Democracies, an expert on Iran's nuclear and missile capabilities.

This comes on the heels of two tranches of sanctions that the Treasury Department's Office of Foreign Assets Control rolled out in February and May in which the administration formally designated a slew of people and entities involved in procuring materials and technology for Iran's missile ballistic program. The sanctions in February followed Iran's late-January test of a medium-range ballistic missile, which other nations said violated a United Nations Security Council Resolution.

Richard Nephew, a lead negotiator of the nuclear deal, told CBS News that he's skeptical that the legislation, if passed by Congress, would be effective in limiting Iran's progress in advancing ballistic missile development. Nephew is currently a senior research scholar at Columbia University's Center on Global Energy Policy and previously served as principal deputy coordinator for sanctions policy at the State Department from 2013 to 2015.

Nephew said he has no problem closing loopholes in existing sanctions law, but he doubts that it would add to the U.S.'s already robust sanctions architecture. He said the measure wouldn't harm the nuclear deal, but added that it also probably wouldn't "affect Iran's ability to engage in missile proliferation."

"I wouldn't blow a trumpet here about how significant this is going to be in actually stopping missiles from being built in Iran," he said.

It's unclear if the legislation is even needed -- the Trump administration already has the authority to execute what is already covered under the bill, Nephew said. Instead, its purpose may be to send a message to Iran and other nations.

These secondary sanctions would comply with the nuclear deal because Iran's missile program is excluded from the agreement. Obama administration officials were unable to win that demand in the deal. While they are separate programs, Iran wants them to operate hand in hand.

"The U.S. intelligence community has concluded that if Iran were to deliver a nuclear device, the delivery vehicle for that nuclear device would be a missile -- a long-range ballistic missile or intercontinental ballistic missile," Dubowitz said.

But the missile itself is not the obstacle for Iran.

"They have a missile right now that could land a warhead in Tel Aviv," Nephew said. "The issue is whether or not they've perfected the kind of warhead that they would need for a nuclear weapon. The [nuclear deal] prohibits that activity...it doesn't help them develop a nuclear warhead."

Status of Iranian nuclear deal

After international inspectors determined that Iran had fulfilled obligations outlined by the deal, the U.S. and European nations relieved sanctions on Iran in January 2016. Inspectors have since been constantly monitoring declared nuclear facilities in Iran and a heavy water reactor to verify that its government is still abiding by the imposed limits.

Those limits, however, will expire over the next decade or so. The agreement says that over the next several years, the U.N. arms embargo will sunset, the U.N. missile embargo will expire, and then a number of nuclear restrictions will begin to expire and accelerate, with many restrictions set to be lifted in 2030.

There's some disagreement about Iran's compliance so far -- some experts say that Iran is obeying the parameters of the deal, while others say its government has violated it. On the same day the Trump administration last announced the ballistic missile sanctions last month, it also announced that it will continue to waive sanctions against Iran as it assesses U.S. policy on Iran.

Dubowitz worries that Iran's "game plan" all along was to give in to temporarily suspending certain nuclear technologies in order to work on more advanced technologies in exchange. He said he's concerned that once the agreement's provisions expire, Iran could emerge with an industrial size nuclear program, "which at that point will have near-zero breakout." "Breakout time" is the amount of time it would take for Iran to build a nuclear weapon -- "near-zero" means it would take Tehran no time at all to produce a nuclear weapon.

Russia sanctions

On Wednesday, the Senate overwhelmingly adopted an amendment in a 97-2 vote into the measure that maintains and expands sanctions against the Russian government. It would, for instance, require a congressional review for any lifting, suspension or termination of U.S. sanctions on Russia, impose mandatory sanctions on entities engage in Russian energy projects and require sanctions to be imposed on people undermining cybersecurity and secondary sanctions on people who contribute to malicious cyber activity. That congressional review is meant to make it far more difficult for the Trump administration to unilaterally lift the Russia sanctions.

It would expand energy sanctions on Russian projects in the Arctic or those that involve deepwater or shale and require the Treasury Department to provide Congress with a study on senior Russian government officials and the influence of Russian oligarch's influence on the U.S. economy.