Ukraine wasn't invaded

Ukraine wasn't invaded because it couldn't defend itself, it was invaded because it tried to defend itself.

Russia has criticized Ukraine's act of increasing its military power before and after the war as provoking its country. Ukraine has reduced its troops to avoid provoking Russia if pro-Russian forces take power, and if anti-Russian forces take power, it has grown its troops against Russia.

Putin's justification for invading Ukraine included not only the attempt to join NATO, but also Ukraine's strengthening of its military power after the occupation of Crimea. And he has continued to insist on demilitarizing Ukraine's military power before and after the war in order to cease the war (if Trump stops this demand from Russia, that is a great achievement).

Neutral diplomacy and self-defense are frequently challenging to work together because the attempt by a weaker country to defend itself is sufficient to stimulate its neighbors. This is due to the fact that a country with considerable military might, even if neutral, is at the border (even if it is significantly weaker than its own) is a factor limiting its hegemony to a powerful country that has to deal with multiple countries at the same time. The neighboring powers must be indifferent if the weaker countries want both to work together.

P.S. Koreans were taught to have suffered from numerous invasions, but at least in the Joseon Dynasty, it was a stable region where there was little risk of being invaded in the history of the world. It is truly a blessing. Japan, which enjoyed 200 years of peace during the shogunate era, may be the only country in the world that had similar good luck.

The experience gained in these exceptional regions cannot be applied to most countries in the world in a much harsher environment than Korea.