Power travels near the speed of light. In theory, the entire globe can be connected and countries with daylight can supply those at night in a cycle.
Most in depth analysis I’ve seen of these Russia - Ukraine conflicts cite this as one of the top factors in why Russia invaded both a decade ago and the most recent war that is ongoing.
That is to say - mutual cooperation agreements like that have enough teeth to keep conflicts to a minimum as the repercussions are severe
Also another ultimate irony is that Russia didn’t completely cut the rest of Europe off from its oil and gas. That symbiosis continues albeit not the same way. Perhaps electricity would be the same
For the past 100+ years, the US has been spending a significant amount of money on protecting oil supplies to protect its oil billionaires and its economy. It's the #1 budget item, outspending the combined military spending of the next 10 economies. This can be reduced to zero, and ultimately, the $ 39 trillion deficit can be eliminated.
The EU is actually extremely special because its souvereign member states collaborate in almost all areas on a level that is unmatched anywhere else. But the ideological foundation is getting eroded by propaganda and if that assault is effective, Europe will balcanize again and end up experiencing many more armed conflicts.
Solar changes the who and where, but really not the what significantly. Solar is far more distributed and less concentrated, and options for distribution are potentially more diverse (cables, direct power beaming, synfuel production and distribution) in ways that an oil-based economy hasn't been.
Even within national borders, power production and distribution are sufficiently centralised and choke-pointed that they are vulnerable to significant disruption, even by non-targeted accidents and natural disasters. Major national and regional power outages are not especially frequent, but neither are they unfamiliar: <https://en.wikipedia.org/wiki/List_of_major_power_outages>.
During periods of conflict, national and irregular forces routinely target power infrastructure, with significant but rarely absolutely crippling effect. For the past three-and-some years, two major eastern-European adversaries have been directly targeting one anothers' energy infrastructure. Though the results are costly, neither has been bombed back to the stone age, or even the pre-electrical era:
"Resilience Under Fire: How Ukraine’s Energy Sector is Adapting – and What It Means for Europe"
<https://rasmussenglobal.com/wp-content/uploads/2025/06/REPOR...> (PDF)
Maybe something like microwave transmission or cheap superconductors will solve it.
Extend that to 10k km and you're looking at approximately 25%, but if it's surplus solar, who cares?
Such a line costs as much as a highway broadly speaking, so it's not impossible to build.
Local power costs are over 30 cents per KWh, so that could be pretty competitive.
The problem is that, no profit based organization will ever build "surplus" solar to enable that kind of thing. If we want surplus power, if we want a strong grid, if we want cheap power, if we want to enable the ability to quite literally waste solar power on inefficient processes (including things like industrial processes that produce less CO2 or generating hydrogen or methane as long term energy storage), we have to get the government to make it happen
But, uh, we hired people who would rather spend $170 billion on harassing random cities and brown people so..... Everyone get ready to pay absurd rates for electricity to support outdated businesses that have been directing American energy policy since Reagan, including paying about 60k coal miners in west virginia for a resource that is economically inferior to other fossil fuels but because they voted for a democrat once they now get a stranglehold on the US economy.
https://en.wikipedia.org/wiki/Xlinks_Morocco%E2%80%93UK_Powe...
There are huge orbortunities for arbitrage in these areas. That's why in Europe there has been significant investment into HVDC connections recently. AFAIK they are mostly (all? ) build privately without special government subsidies (over the usual ones that all large infrastructure projects always seem to get). I think this partly the beauty of the renewable revolution, it
I think what we seeing in a lot of places now is quite the opposite. There are significant opportunities for arbitrage, so private entities are building HVDC lines in Europe for example (without special subsidies over the usual ones that all big infrastructure always seems to get AFAIK). That's part of the beauty of the renewables revolution it breaks up the stronghold that only a few big corps held over generation.
My understanding of the intentions of connecting international grids is for things like emergency supply of electricity to a different grid to stabilise the frequency and prevent blackouts.
I also know breakers for HVDC are extremely challenging to make, AC power has the benefit of sine waves crossing the zero line so power can be switched/broken a lot easier than with DC.