>"Actually, they were caused by lack of food."

This is a tautology; a lack of food can't be caused by a lack of food, as it is a lack of food.

>"Yes, which of the 757 million food insecure people is Putin responsible for their food insecurity?"

In Putin's case, he has caused the price of food to increase through his war on Ukraine, as the cost of fertilizer makes many agricultural products uneconomical to grow for customers in less-developed nations.

>"But it doesn't change the fact that we could spend money and feed most of the people who are going hungry"

There was food literally rotting away (elsewhere in India) during the 2013 drought in Maharashtra, but it wasn't possible/worth transporting it to the affected region (due to government interference).[1] In places like Bangladesh, recent governments have used famine as a tool for obtaining foreign aid while also exterminating or weakening opposition.[2] During the 1990s North Korean famine, plenty of food was offered to the regime, but it was mostly rejected, and that which was accepted was not widely distributed. [3]

[1] https://en.wikipedia.org/wiki/2013_drought_in_Maharashtra

[2] https://asianews.network/over-a-quarter-of-bangladeshis-suff...

[3] https://en.wikipedia.org/wiki/1990s_North_Korean_famine#Fail...

I'm not arguing that governments don't cause famine directly or indirectly, I'm arguing that there are very few examples of govs that won't let food aid in. Or, enough food aid. For those specific cases, yes the only solution is to engage with the government - either pressuring them diplomatically, or by use of force. But for everywhere else, where people are going hungry because of poverty and neglect, the thing they need is literally just food, and someone willing to spend the money to get that food to them.