North Korea’s nuclear test this week is also putting the spotlight on Iran, which has been moving forward on its nuclear program despite Western and U.S. opposition.
There were celebrations in North Korea, where the country's latest nuclear test is being publicly hailed.
But as worldwide condemnation pours in, there is also the recognition that the test goes beyond the saber-rattling of Pyongyang.
"This is about proliferation and this is also about Iran," noted U.S. Secretary of State John Kerry. "Because they're linked."
Experts say tough talk alone is unlikely to resonate in Iran, so what Tehran does next may very well depend on how the world backs up similar talk to North Korea.
“If you want to prevent Iran from getting the bomb you have to take a hard line against North Korea,” stated Raymond Tanter, former U.S. National Security Council member. He says that so far, Western resolve has not been strong enough.
“If you allow North Korea to get away with miniaturizing [a nuclear bomb], with three nuclear tests, with any number of missile tests, that signals to Iran that a nuclear-armed North Korea can get away with murder and therefore Iran will not be deterred from getting the bomb,” Tanter added.
There are indications Iran and North Korea are helping each other, having signed a deal late last year to cooperate on a variety of scientific endeavors.
That type of collaboration has been a concern in Washington for years. And some analysts now warn it is clear Iran has been sharing its expertise on uranium enrichment in exchange for Pyongyang's superior missile technology.
That strategy of cooperation is not without wide-ranging risks.
"In Iran, what we’re seeing is that their nuclear facilities can be identified, they can be theoretically attacked in a limited operation,” noted Brookings Institution scholar Michael O'Hanlon.
Iran has repeatedly denied its nuclear program is for anything other than civilian purposes.
At his State of the Union address, U.S. President Barack Obama, warned that Tehran will only be allowed to push so far. "We will do what is necessary to prevent them from getting a nuclear weapon," he said.
How that will be done may depend on the outcome of talks expected later this month between world powers and Iran.