Here is one excerpt of many substantive points:
Numerous studies have formally tested for relationships between foreign aid and conflict,using a range of identification strategies to obtain credible causal estimates. Many studies find that foreign aid can increase conflict. Nunn and Qian (2014) find this to be the case for U.S. food aid. Their analysis uses an IV strategy where U.S. wheat production shocks, combined with a country’s tendency to receive wheat aid from the U.S. to obtain exogenous variation in U.S. food aid supply. Crost, Felter and Johnson (2014) use an RD strategy that exploits an eligibility cut-off for a World-Bank-funded development program in the Philippines to estimate the effects of the program on conflict. They find that eligibility to participate in the program is associated with more conflict, which appears to be due to an increase in insurgent attacks against government forces in an attempt to disrupt the program. Dube and Naidu (2015) estimate the effects of military aid in Colombia using a differences-in-differences identification strategy. They find that U.S. military aid leads to an increase in conflict and violence arising due to an increase in attacks by paramilitaries…
While there is evidence that foreign aid can increase conflict, it is not the case that it always leads to conflict. For example, Nunn and Qian (2014) show that among the countries in their sample without a recent history of past conflict, food aid does not increase conflict. In a follow-up study that studies a conditional cash transfer program also in the Philippines, Crost, Felter and Johnson(2016) find that this aid package actually decreased conflict. Trisko Darden (2020) finds that the effect of U.S. aid on state killings and repression of its citizens is weaker following the end of the Cold War.
Given the evidence that foreign aid can sometimes cause conflicts, but at other times have no effects or even reduce conflict, the natural next question is how we implement foreign aid projects in a manner that minimizes its harm, thus maximizing overall benefit.
That is from a recent and really quite excellent talk on development by Nathan Nunn. He also has an especially interesting discussion of the geographic centralization of RCTs in economics among numerous other points of note. Recommended.