I'd like to ask about the meaning of the last sentence in the following passage:
According to the research, most collaboration between government institutions and the NGO sector, regardless of the area and scale of their activities, takes place within projects funded by donors. Since donors prefer to fund one-off and short-term projects, the government-NGO relationship tends to be temporary and unsustainable. In fairness to the donors, it should be pointed out that, by requiring NGOs to involve the government and its institutions in their projects, donor grants have acted as a massive incentive to establishing the government-NGO relationship in the first place.
Does the last sentence imply that it is donors who require NGOs to involve the government and its institutions in their projects?
And does "by" mean when/while here, or is it the usual meaning of "by" as in "what do you mean by saying..."?