The Pentagon released a document addressing Washington adversaries for their refusal to step down on their usage of nuclear weapons in their national security strategies. The document, based on this premise, speaks of high probability of using nuclear weapons in future conflicts. 

This could be deemed a (very lethal) update in US military doctrine, which is based upon the declaration of the potential for nuclear weapons use in "regional and global conflicts." 

The Pentagon document, which has taken its full approval to be publicized this month, claimed that "Since 2010, no potential adversary has reduced either the role of nuclear weapons in its national security strategy or the number of nuclear weapons it fields. Rather, they have moved decidedly in the opposite direction."

Furthermore, the document allegedly states that while the United States "has continued to reduce the number and salience of nuclear weapons, others, including Russia and China, have moved in the opposite direction. They have added new types of nuclear capabilities to their arsenal, increased the salience of nuclear forces in their strategies and plans, and engaged in increasingly aggressive behavior."

North Korea was also addressed, saying that "North Korea's continued pursuit of nuclear weapons capabilities poses the most immediate and dire proliferation threat to international security and stability." 

As for the “Iranian threat,” according to the document, the danger lies in the development of “long-range ballistic missile capabilities, and [Iran's] aggressive strategy and activities to destabilize neighboring governments."

Finally, the US military warned against "Russian-Chinese integration to develop weapons," while the commander of US space operations, John Raymond, warned against America's opponents using outer space as a battlefield and using weapons "that can target American satellites."

It is interesting to note that while the United States owns over approximately 5500 nuclear warheads, China owns 320, as of June 2020. North Korea stoops lower than that number, allegedly owning a 'meager' 40 in total - Iran, on the other hand, has no registration of nuclear warheads.

In numbers, the most 'sincere' and realistic threat to the United States could be Russia, which owns over 6000 nuclear warheads.