The Afghan Air Force has had to
In 2012 Afghanistan announced that it would cancel the contract to buy and use 20 C-27A transports. The official reason was the inability of the Italian maintenance firm to keep the aircraft operational. The unofficial reason was the unwillingness of the Italians to pay as much in bribes as the Afghan officials were demanding. Over half a billion dollars was being spent on buying and operating the C-27s and all the money was coming from the United States. Afghan government and air force officials were determined to grab as much of that cash as possible. That meant there was not enough money for the spare parts and tools needed to keep the C-27As flying.
The Afghans can be self-destructive in so many ways, and letting these transports get away because not enough could be stolen from the contracts was another example.
. . .
In an effort to get past the epic and durable culture of corruption in Afghanistan the U.S., which supplies all the money for the Afghan security forces, obtained a different kind of maintenance contract for the four Afghan C-130Hs, Details of this deal were worked out by 2019. What makes this deal work is that Afghans have nothing to do with handling the maintenance money. There was also tighter controls over Afghan access to stocks of valuable spare parts (which, if stolen, will fetch a price on the black market). This deal costs about $10 million a year for each of the C-130Hs.
There's more at the link.
It sticks in my craw that the USA is pouring good money after bad into the sinkhole of corruption that is Afghanistan. Even worse, we're pouring the lives of our service personnel down the same hole! Of what strategic or geopolitical importance is Afghanistan to us, to justify the expenditure of one more US taxpayer dollar or one more American life?
Unless a serious, meaningful answer to that question can be given - and I haven't heard it yet - I think there's no longer any justification for keeping US forces in that country.
Some claim that the Taliban would take over again as soon as we left. So what? Let them run that hellhole of a country for themselves, and see how they like it - particularly without the cornucopia of US aid to subsidize them! Others argue that Afghanistan would simply become a center for international fundamentalist Islam, ripe for ISIS or Al Qaeda or another group to set up their base there and export terrorism worldwide. Yes, I suppose that's a risk . . . but the present situation doesn't appear to have stopped such terrorist organizations from functioning, does it? Would the world be any worse off if they were shunted off the beaten track into Afghanistan? I can't see how.
I've been saying for years, along with many others, that no military solution is possible in Afghanistan. Any serious student of history will agree. As far as I'm concerned, this is yet another reason why President Trump should cut the Gordian knot and bring our forces home from Afghanistan. Enough is enough.