The United States maintains a robust nuclear arsenal deployed on a triad of strategic delivery

systems, including land- and submarine-based long-range ballistic missiles and nuclear-capable

bombers. In addition, it also has a significant number of nonstrategic and nondeployed warheads not constrained by US-Russian arms control treaties. Over the next thirty years, the United States plans to spend approximately $1 trillion maintaining the current arsenal, buying replacement systems, and upgrading existing nuclear bombs and warheads. Procurement of replacement platforms and associated warheads will peak during a four to six year window, sometime after 2020. If current projections hold, the United States will spend 3 percent of its defense budget on procuring new strategic systems during these peak years. This percentage is comparable to spending for procurement of new strategic systems in the 1980s under President Ronald Reagan.

Perhaps no other weapon in the U.S. arsenal has proven as numerous, expensive, and unusable as the nuclear warhead. 

The nuclear paradigm that existed over the course of the Cold War no longer holds relevancy in today's world. The foe that threatened the existence of the United States over that nearly half-century period no longer exists. More than 20 years after the end of that mortal threat, the United States is still postured to fight an enemy that does not exist. In the meantime, there are real 21st century threats the U.S. is not confronting adequately. 

In March of this year, US President Barack Obama told a group of campaign donors that "loose nukes" were the main thing keeping him up at night. This sentiment is consistent with his administration's stated policy, which is to keep wayward nuclear weapons and radioactive material out of the hands of terrorists.

Analysts say a possible 3-year computer offensive has targeted details on U.S. nuclear diplomacy with Iran, the Wall Street Journal reports.

Technology has been long understood to play a central role in limiting the proliferation of nuclear weapons. Evolving nuclear technology, increased access to information, and systematic improvements in design and manufacturing tools, however, should in time ease the proliferation challenge. Eventually, even developing countries could possess a sufficient technical ability. 

Winning global support to phase out the civilian use of highly enriched uranium (HEU) has been one of the seminal achievements of the Nuclear Security Summit (NSS) process that President Barack Obama started four years ago.

For decades, the United States has sought to secure and minimize the worldwide use of this dangerous material. Important US-led efforts such as the Global Threat Reduction Initiative have successfully eliminated civilian HEU in over two dozen countries, removing enough material to build 200 nuclear weapons. However, broader international efforts have been too often hampered by a lack of multilateral support.

Russia plans to sign a contract with Iran this year to build two more nuclear reactors at its Bushehr power plant as part of a broader deal for up to eight reactors in the Islamic state, a source close to the negotiations told Reuters on Thursday.

Iran and the so-called P5+1 [the United States, UK, France, Russia, China, and Germany] are unlikely to reach an agreement on the former's controversial nuclear program by the stated goal of July 20, says George Perkovich, director of Carnegie's Nuclear Policy program, but he feels a partial accord is possible by the end of the year. The biggest challenge, he explains, is on the issue of uranium enrichment-Iran wants to more than double its nineteen thousand centrifuges while the P5+1 wants to limit this number to about four thousand. Perkovich says that opponents to nuclear diplomacy in both countries will likely try to leverage the missed deadline to derail the process.

The Associated Press has documented evidence of security problems, low morale and other troubles in the nation's nuclear forces. On Thursday, the AP reported that security forces at a nuclear missile base in Montana failed a drill designed to test their ability to respond effectively to a simulated hostile takeover of a missile launch silo.

The version of the fiscal 2015 defense authorization bill that the House approved Thursday would cut some controversial nuclear weapons spending in a bid to help veterans.

The Third Workshop on Civil Liability for Nuclear Damage was held on 19 May 2014 at the IAEA Headquarters. The Workshop introduced diplomats and experts from Member States to the international legal regime of civil liability for nuclear damage. 

What is the best way to prevent countries from acquiring nuclear weapons? The vast majority of nonproliferation efforts attempt to control access to sensitive technologies. However, a new study by Scott Kemp, an assistant professor in MIT's Department of Nuclear Science and Engineering, suggests that this approach might not be working. In an article published tomorrow in the journal International Security, Kemp examines the history of the most common proliferation technology - the gas centrifuge, used to extract a weapon-suitable isotope of uranium from a larger supply of that element - and finds that existing nonproliferation policies would not have stopped historical instances of its development. Kemp, a former science advisor for nonproliferation in the U.S. State Department, argues that governments need to reinvent how they look at nuclear proliferation in the modern age, turning their attention to the security threats and status symbols that motivate states to seek nuclear weapons in the first place. He talked with MIT News recently.