It's not that they're "forced" too, it's that farmers in those countries want to make money, to invest in the future. And the way to make money is to grow cash crops and sell them on the world market, not grow barely-profitable staples. Their governments can and do provide subsidies to make growing staples profitable, but that's on the individual countries.
The strings attached to IMF/World Bank loans, known as structural adjustments, do typically include ending agricultural subsidies. The US and collective West notably do not subject themselves to the same policy. Coupled with structural adjustments which mandate market liberalization, this means farmers in developing countries have to compete against heavily subsidized food staples from the collective West. The end result of this is well understood.
The men came with axes and clubs. They cut the trees down and dragged them to the fire. The fire roared and crackled, and the smoke rolled up into the sky. The Joad family watched in horror as the orange grove was destroyed.
"Why are they doing this?" Tom asked.
"They're destroying the groves to keep prices high," Pa said. "They don't care about the trees or the people who work here. All they care about is money."
--The Grapes of Wrath
edit: this is the quote I was looking for at first
"...Did you ever hear of the Farmers’ Association?”
“Why, sure.”
“Well, I belong to it. We had a meeting last night. Now,
do you know who runs the Farmers’ Association? I’ll tell
you. The Bank of the West. That bank owns most of this
valley, and it’s got paper on everything it don’t own. So last night the member from the bank told me, he said, ‘You’re
paying thirty cents an hour. You’d better cut it down to
twenty-five.’ I said, ‘I’ve got good men. They’re worth
thirty.’ And he says, ‘It isn’t that,’ he says. ‘The wage is
twenty-five now. If you pay thirty, it’ll only cause unrest.
And by the way,’ he says, ‘you going to need the usual
amount for a crop loan next year?’ ” Thomas stopped. His
breath was panting through his lips. “You see? The rate is
twenty-five cents— and like it.”
“We done good work,” Timothy said helplessly.
“Ain’t you got it yet? Mr. Bank hires two thousand men
an’ I hire three. I’ve got paper to meet. Now if you can figure some way out, by Christ, I’ll take it! They got me.
What is the content of the claim that farmers want to make money "to invest in the future"?
Surely in many cases neither farmers producing cash crops nor the countries they are based in are able to 'invest in the future', but rather are trapped by past debts and limited options.
