The new diplomat on the block: Kerry’s tough take on Syria and Iran

Martha Raddatz, Richard Coolidge & Jordyn Phelps
Power Players

On the Radar

At the end of his first overseas trip as secretary of state, John Kerry says the international community is facing a "challenging moment" in negotiating a peaceful solution with Iran over its nuclear program and says the United States, along with the other countries involved in aiding Syria’s opposition forces, has "ratcheted up support" to bring an end to the two-year long conflict.

The newly minted secretary of state says that while Iran has been allowed to cross red lines in the past, President Obama is determined to prevent Iran from obtaining a nuclear weapon.

"This is a very challenging moment with great risks and stakes for everybody because the region will be far less stable and far more threatened if Iran were to have a nuclear weapon," Kerry tells On the Radar. "It will spur a nuclear arms race. It has risks for greater terrorism. It will be destabilizing."

And while the stakes are high with Iran, Kerry says the level of cooperation among the international community has never been stronger.

"Right now you have the most significant cooperation in history between Israeli intelligence, American intelligence, other intelligence entities," Kerry says. "We are prepared through P5+1 and negotiating process to engage in a serious proposal that they would make to prove their program is in fact a peaceful program."

On the topic of Syria, Kerry says President Obama, along with his predecessor Hillary Clinton, have laid groundwork in placing sanctions on the Syrian regime and determining who the opposition forces are, and now it's time to make clear to Syrian President Bashar Assad that his killing campaign against the Syrian people will not be allowed to continue.

"There is a holistic, united effort now that is focused on trying to save lives in Syria, and make it clear to President Assad that we are determined and that he needs to think hard about his calculation in raining scuds down on his population," says Kerry. "I think he has thought up until now, that he can simply have Hezbollah and Iran and some of the weapons coming from Russia, that he could sit there and shoot it out. And if that's his calculation this new increase of effort is to make it clear to him he's wrong."

Kerry says that every country involved in resolving the Syria conflict has "ratcheted up" support following a meeting last week in Rome, but stopped short of saying that the United States would become military involved.

"That's the President of the United States' decision and I don't think this is a president who takes any option off the table but for the moment he feels like what we're doing is the right policy," Kerry says.

To hear more of the interview with Kerry, check out this week's On the Radar.

ABC's Alexandra Dukakis and Matthew McGarry contributed to this episode.