The tension between NATO and Russia has played a part in the country’s devastating attacks on Ukraine, with Russian President Vladimir Putin insisting his security demands on the security alliance have been ignored.

Russia has demanded a legal guarantee that Ukraine be denied NATO membership, even though NATO has never excluded potential membership for any European country. However, there are no plans in the foreseeable future for Ukraine to join the organization.

Ukraine’s desire to join NATO has intensified since Russia seized the Crimean Peninsula and instigated a rebellion in eastern Ukraine in 2014.

Putin has argued that a further eastward expansion of NATO would be a security threat to Russia. The U.S and its allies have denied this is a valid worry, as no NATO country is threatening force against Russia.

NATO was formed after World War II to act as a check on the Soviet Union’s pressure campaigns in Eastern Europe. Its strength varied throughout the Cold War.

After the Soviet Union’s collapse, several of its former members expressed a desire to join NATO, so the organization created a pathway for them to do so.

Several countries, such as Hungary, Poland and the Czech Republic, embarked on that road and became the first Eastern European nations to join NATO in 1999.

In 2004, seven Eastern European nations joined NATO at once. Russia has tried to join NATO multiple times, but the nation has been repeatedly rejected.