The Iran nuclear deal raises searching questions here about what may be a far more troubling nuclear problem: North Korea's success in building nuclear warheads and a missile system for delivering them to distant targets.
Chinese intelligence sources this winter briefed American officials that Pyongyang now has as many as 20 nuclear devices.
For South Korea, separated from the North since the end of World War II, the agreement to limit and forestall Tehran’s nuclear program holds out potential for toning down North Korea's rigid adherence to nuclear weapons as its best defense against all perceived threats.
The South's unification minister, Hong Yong-pyo, was blunt in comments Tuesday about what to expect. "Conclusion of Iranian negotiations will not lead to solution of the nuclear problem” in North Korea he told foreign correspondents here. But as the North now represents "the only country … to exercise nuclear power to intimidate the rest of the world…the agreement will at least give some pressure on North Korea."
It is not known whether negotiators in Vienna discussed or agreed privately to address the broader issue of Tehran’s assistance or cooperation with Pyongyang.
Will Tehran stop aiding Pyongyang?
Analysts like Scott Snyder of the Council on Foreign Relations say that how North Korea now responds to the new deal "ultimately will depend on whether US negotiators also have a tacit understanding with Iran to curtail questionable relationships with North Korea in these areas.” If North Korea "loses another customer," Mr. Snyder believes, "Pyongyang may take notice."
So far Pyongyang has kept its silence. The North Korean media has yet to report on the historic accord with Iran, much less offer any commentary.
The Iran deal does give Pyongyang something new to worry about, says Mark Fitzpatrick at the International Institute for Strategic Studies in London. "I bet their gut reaction will be along the lines of, ‘We are more isolated than ever, with even Iran making peace with Washington,’" he says.
Still, the lesson that young North Korean leader Kim Jong-un “should draw” from 20-months of intensive talks between the international community and Iran, "Is that there is no harm in entering into negotiations with the US and possibly much to gain if [one is] willing to make compromises.”
'Defining nonproliferation down?'
Might the untested new leader calculate that it is time to tone down North Korea’s usually bombastic rhetoric and test the waters? Nicholas Eberstadt, long-time analyst at the American Enterprise Institute, thinks so. He's critical of the deal as a “relaxation of nuke rules for Iran” and thinks that Mr. Kim can take advantage of it.
"The Iran deal is a prime example of the phenomenon we might call 'defining nonproliferation down,'" Mr. Eberstadt says, meaning that standards have been lowered. “Pyongyang could hardly but expect to be a beneficiary," he adds.
On the Korean peninsula itself, there are some small signs of easing tensions: North and South negotiators are due to meet Thursday at the Kaesong economic complex inside North Korea to discuss wage demands for 55,000 North Koreans employed there.
Then, early next month, Lee Hee-ho, the 93-year-old widow of Kim Dae-jung, the former South Korean leader who engineered a “Sunshine policy” of reconciliation, will go to Pyongyang for four days.
Ms. Lee's visit is expected to revive memories of the historic June 2000 visit when she accompanied her husband to a summit with North Korean leader Kim Jong-il, father of the current leader.
North Korea often harks back fondly to the June 2000 summit and the decade of the Sunshine policy when South Korea shipped half a million tons of food and fertilizer annually to North Korea. South Korea cut off the aid in 2008 and restricts such programs under special circumstances for "humanitarian" reasons.