The emotional reaction you are describing is just 'I don't like Japan, therefore any news of Japan increasing its defense makes me upset', and honestly I don't think this sentiment has any reasoning behind it, and doesn't need to be justified or defended, but in the same manner, it doesn't need to be heeded.

Nations don't make security decisions based on the hatred of other nationals, or whatever hurt feelings they might have, they make spending decisions based on their own security needs.

In the case of Japan, it has serious security needs because the US is much weaker now and cannot provide a defense shield, whereas China is both much stronger and also is making expansive territorial claims in the South China Sea. That calls for more defense spending just as a rational response. It also calls for Japan to update its constitution as the postwar arrangement comes to an end, which they will do, and they will also develop nuclear weapons.

Honestly it makes no sense for South Korea to not have a nuke if North Korea does. When you have a conflict between two nations, and one acquires nuclear weapons, the other side is driven to do the same. Look at India and Pakistan. In the past, the US kept a lid on things because it had such overwhelming dominance that it could be a global policeman and in that environment, individual nations didn't need to provide for their own defense, they had a policeman to back them.

But that era is now over, and as much as people complained about the US strutting around like a global cop, they are about to see the consequences of a world without a global cop -- that is, the world as it normally exists. In that world, it makes no sense for Japan to not have a nuke if North Korea and China does, and soon South Korea will, too. My guess is that South Korea will go nuclear first.

Just as it makes no sense for Iran to not have a nuke if Israel does. This is not a matter of hurt feelings, it is a matter of security balancing. It doesn't matter if you don't like Iran, or if you do like it, it's just a question of nations taking care of their own survival.

All of this will happen, and we will look back on the period of non-proliferation as being an artifact of US global dominance, understanding that as US military dominance fades, nations will turn to measures of self-help in a hostile world.

The whole world is changing, and we should face it with clarity and wisdom, not with hurt feelings. There are all sorts of repercussions to global trade, to global security arrangements, that are changing right now, and it helps to have your eyes open and think "well, how would each nation respond to this new threat environment" in a deliberate and realist perspective, rather than whether you like a given country or not.

One example is what is happening right now in Saudi Arabia. The US promised to be Saudi's security guarantor in 1945, and historically the US has done this, but this is a role that the US can no longer play, so Saudi Arabia is now being beaten by Yemen, and is desperately appealing to the US for help, but there is little the US can do. Now Saudi Arabia is in a pickle -- it will also turn to nuclear weapons.

One thing to think about is the moral hazard of these types of security guarantees - they incentivize client states to provoke their enemies, in this case Saudi Arabia invading and occupying Yemen, installing a puppet government, and blockading the nation. When you have the US at your back, you can take these provocative actions. But then comes a moment when you look behind and the Big Brother is no longer there.

Then we can look at Europe, you have this demilitarized continent that is doing things like seizing Russian ships because they are confident that the US will step and fight a war with Russia on their behalf. Well, they are going to learn that reality has changed and the US no longer has the power projection capability it once did. And what will they do? My guess is that at least one European state will nuclearize.

We are going to see major shifts happen as nations regionalize, many nations nuclearize, and new regional trade blocs form that disrupt global capital flows that we have taken for granted, especially if you formed your view of reality in the era when there was a Global Cop that had your back.