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The Ukrainian ambassador to the U.S. says that Ukrainians are spending days in shelters and babies are born underground.

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Russian President Vladimir Putin has put his nuclear forces on high alert.

The United States and its NATO allies have imposed a number of sanctions on the country in order to de-escalate the situation.

Putin is the one who is attacking. This war was chosen by Putin. Biden said during a White House press briefing on Friday that he and his country will bear the consequences.

Putin told his top officials to be ready for a special regime after NATO made aggressive statements about his country.

Nuclear deterrence is a question. Here is what you should know about it, as well as the nuclear capabilities of Russia and NATO allies.

Russian President Vladimir Putin visits the National Space Centre construction site in Moscow on February 27, 2022.
Russian President Vladimir Putin visits the National Space Centre construction site in Moscow on February 27, 2022.

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What is nuclear deterrence?

Nuclear deterrence was used in the Cold War to prevent nuclear aggression.

If the Soviet Union or any nation attempted to attack the U.S., it would respond swiftly and launch an even bigger weapon.

The same strategy is being used by Putin. If the U.S. and other NATO allies impose heavy sanctions against the Russian economy, Russia will be prepared to use nuclear weaponry, according to the Russian president.

Putin had previously said any country that would face consequences that they had never encountered before.

What is DEFCON?

DEFCON is an acronym for Defense Ready Condition and it is used by the Pentagon to indicate the level of threats the country faces from other nations.

DEFCON 1 to 5 are the levels. DEFCON 5 is the lowest state of readiness and DEFCON 1 is the highest state of readiness. For security reasons, officials never publicly state which DEFCON level the country is under.

The U.S. has never made it to DEFCON 1. DEFCON 2 is thought to have occurred during the Cuban Missile Crisis. There is no official declaration of the country's DEFCON status, but there is a lot of speculation on the internet.

Russia has its own version of DEFCON. The founder of The Alperovitch Institute for Cybersecurity Studies, a former chief technology officer of CrowdStrike, said that Russia has four levels. The second level similar to the U.S. is the Elevated level.

What is NATO? Russia is trying to forbid membership in the military alliance.

Does NATO have nuclear weapons?

NATO members have nuclear weapons, but they are only used for deterrence. The country has full control of any weapons deployed in Europe, and these weapons mainly come from the U.S.

Should an adversary decide to attack NATO, they must contend with NATO's decision-making, but also make a judgement about decision-making from the leaders of the United States, United Kingdom, and France, according to the organization.

A senior Defense Department official told reporters that Russia is not under threat from the U.S. and NATO.

USA TODAY staff reports.

You can follow Jordan Mendoza on social media.

This article was first published on USA TODAY: What is DEFCON? Nuclear deterrence means what it says. Here is what to know.

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