The news that North Korea’s leader Kim Jong Un has offered to hold talks about getting rid of his nuclear weapons has fueled new hopes that the deadly standoff with North Korea may be easing. So far, only South Korea has said these talks will happen. While it remains to be seen what exactly North Korea has offered to discuss if it does indeed confirm its participation—it’s speculated that sanctions relief in exchange for some technical steps to roll back North Korea’s nuclear efforts will be on the negotiating table—it is already clear that Kim, following his successful Olympic charm offensive, is ready to continue playing peacemaker.

President Vladimir Putin has warned that he would not hesitate to strike back if Russia was hit by a nuclear adversary, even if it led to a “global catastrophe.” The Russian leader spoke to one of his country’s most infamous pro-Kremlin TV show hosts, in a tough-talking interview broadcast on national airwaves before Russians go to the polls later this month.

So far, Saudi Arabia has done things that suggest it doesn’t want nuclear weapons. It is a party to the nuclear Non-Proliferation Treaty and has a comprehensive inspection agreement with the International Atomic Energy Agency (IAEA). Last year it voted for the Nuclear Weapons Ban Treaty at the United Nations. The Saudis have informed the IAEA, the United States, Russia, and others that they want to build nuclear power plants to generate electricity, advance their technology basis, and reduce their dependence on fossil fuels. Because of Riyadh’s enmity toward Tehran, there is concern it might, like Iran, try to secretly enrich uranium that could be used for power or to build nuclear weapons. Unlike Iran, the Saudi nuclear infrastructure is rudimentary, with no clear path to an enrichment capacity. For security and commercial reasons, none of the countries enriching uranium to make nuclear fuel will likely share their technology.

As China and Russia threaten to overtake the U.S. with new technologies, development of hypersonic capabilities is the “highest technical priority” for Michael Griffin, the Pentagon’s new undersecretary of defense for research and engineering. “I’m sorry for everybody out there who champion some other high priority, some technical thing; it’s not that I disagree with those. But there has to be a first, and hypersonics is my first,” Griffin said at the McAleese/Credit Suisse conference Tuesday, in his first public comments since taking office 10 days ago.

Iran intends to again accuse the United States of violating the landmark 2015 nuclear accord between Tehran and world powers at next week's meeting on the agreement in Vienna, a senior Iranian diplomat said Wednesday. "The U.S. is regularly violating the nuclear deal and this is a source of concern for Iran. Therefore, we will raise this issue in Vienna," Iranian Ambassador to Britain Hamid Baeidinejad said in an interview with Kyodo News in London.