You're conflating care and pride.

No, I'm connecting them. That's the point. I did not say that they were the same thing. Rather, that one motivates the other.

There's a very rational reason for caring about one's own home

Rational is all well and good, but it doesn't motivate people in the same way that emotional attachment does. You can't argue someone into or out of an emotion with good reason.

I'm pretty sure we've seen more of the opposite, where rampant nationalism or similar leads societies to disaster.

My point is that rampant nationalism (the national form of narcissism) is an outward symptom of self-loathing. You're making my argument for me.

Personally I think a fair amount of the damage that the US is doing to itself now is a result of foreign influence campaigns repeatedly targeting the US's worst international blunders.

Evidence?

If I had direct evidence of the conclusion, I would not have begun with the qualifier "Personally I think". Do you generally struggle with reading comprehension?

I can point to evidence that Russia in particular has a pattern of sowing division within target countries in order to destabilize them, usually followed by political or military pressure of some kind:

https://forbiddenstories.org/propaganda-machine-secret-documents-reveal-russias-foreign-influence-strategy-across-three-continents/

https://thewalrus.ca/the-russian-money-behind-albertas-separatist-movement/

Russia has used social media to destabilize former Soviet states such as Ukraine and Western nations such as France and Spain. It has been suggested that since 2019, Russian-sponsored troll accounts and bots have formed and taken over prominent left-wing and right-wing subreddits on Reddit, such as the antiwar, greenandpleasant, and aboringdystopia subreddits, "suggest[ing] a Russian-led attempt to antagonize and influence Americans online, which is still ongoing." Canadian subreddits have also been directly targeted by Russia.

Russia's numerous disinformation attacks including support for white supremacist activities and attacks of Biden's mental fitness were utilized by Donald Trump, senior Trump Administration officials, and his re-election campaign.

The Washington Post reported in April 2024 that the Russian foreign ministry was using disinformation to weaken Western countries, in particular the United States. The document was said to be the first official confirmation of such policies and The Washington Post observed Russian attempts to disrupt American and European domestic politics. It also said this was done to shift the balance of power to Russia and other Second World countries such as China, Iran, and North Korea. The Guardian reported Russia was seeking to spread conspiracy theories among the American far right to undermine support for Ukraine. Voice of America reported that Russian disinformation campaigns have focused on promoting American isolationism, tensions between various races as well as border security concerns. The Telegraph reported that Russia and China were promoting pro-Palestinian influencers in order to manipulate British public opinion in favor of Russian and Chinese interests.

https://en.wikipedia.org/wiki/Russian_disinformation

This is standard practice for Russian foreign policy - essentially astroturfing on social media to create social disruption, while also specifically inflaming and amplifying existing groups of malcontents.

There's a very rational reason for caring about one's own home, and that's the fact that you live there.

As opposed to your country, where you clearly don't live?