“Because Russia is and was a hostile country to us...”
And you don’t think there are a few others who are of a similar attitude?
NATO was formed before the Warsaw Pact (1954 - USSR fall) to meet a perceived threat from the USSR in the North Atlantic Regions. The Warsaw Pact was disbanded. Why hasn’t NATO disbanded? Why instead has it expanded (and seeks to expand everywhere beyond its charter territories?)
Russia is a threat. So is China, so are most Arab countries. So are India and Pakistan for that matter - and Iraq, Afghanistan...... Include all of the banana republic countries to our south and you have a whole bunch of threats to varying degrees. None of them are peaceful
Nato was not disbanded because we had other threats and because we didn’t trust Russia yet and that turned out to be justified. The Warsaw pact was disbanded because the captive nations escaped, and Russia was all alone. The other threats you mentioned are all quite manageable and are a justification for keeping NATO in tact.