If you want to understand this, start with the classic Why Big Nations Lose Small Wars: The Politics of Asymmetric Conflict - https://news.ycombinator.com/item?id=47346164
Ever since I consciously read and listened to people talking on tv and radio, so somewhere in the nineties, I heard countless military strategists explain why the war mongers in the USA were stupid to even think about subduing Iran by attacking them. Geography alone makes it impossible.
The current situation is not a consequence of modern warfare. It’s a consequence of the many layers of hubris, stupidity and arrogance uttered by incompetent people who put up a show for a shrinking audience.
The stupidity of the leadership in the USA is perfectly broadcasted in full view, for everyone to see, during Trump cabinet meetings, where he is undeservedly praised by weaker men and women. It shows all the weaknesses of the USA in just 5 minutes of watching that cringefest. You don’t even need spies.
"There are other similarities between Ukraine and Iran. Both are wars instigated by the leaders of great powers in the apparent belief of easy victory. Both have developed in ways those leaders did not anticipate into something like a stalemate—stalemates in which, for Russia and America alike, a lack of victory looks increasingly like defeat. Are technological changes making the role of the defender easier? Or systematically encouraging big powers to start wars they cannot win? Or is this merely a case of business as usual—great powers blundering into ill-advised wars that reflect the prevailing technologies of the day?"
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Putin was advised that Russian disinfo had worked and Ukrainians would welcome Russian troops as liberators while Zelensky's government would fold immediately. His generals feared to offer a less rosy assessment because doing so would have been immediately fatal. Trump was advised that invading Iran was a very bad idea[1]. Putin's brutality led to him being misinformed, but Trump ignored good information and made a bad decision.
New technology didn't cause either of these bad decisions. It was old-fashioned arrogance, thuggishness, and stupidity.
As for drone warfare... A real X factor is going to be production capacity.
Ukraine has managed to capture manned Russian positions with only drones. Drone tech evolves so quickly that one side's technological edge can be blunted or even reversed in just a few weeks or months. Stockpiles are not to be relied upon. Being able to out-evolve the enemy is critical, but being able to turn lessons learned into new hardware immediately will likely be a deciding factor in future conflicts.
[1]https://www.bbc.com/news/articles/cn0zrwzr519o