In the Arab and Muslim worlds, the entire carrot idea is not only ineffective, but it is derided as a perfect example of Western stupidity. It is as if both the scientists and the laboratory rats are convinced that each one has conditioned the other one to behave in the way they want. Paying off a party who is already resentful or hateful does not tend to make them change their minds nearly as much as it is supposed.
A perfect example of this comes from an Al Ahram article from last week, talking about the wisdom of Camp David from Egypt's perspective by countering arguments of those who were opposed. The last section has this very instructive section (h/t Judeopundit):
The last charge against the Egyptian-Israeli Peace Treaty that I would like to address here is that which maintains that it turned Egypt into a US dependency. The contention could only come from someone who is not quite mentally stable, or that has never read history, or that does not know the true nature of Egypt, the Egyptian people and the Egyptian government. Clearly, no rational person would fail to take the world's sole superpower into account. But all that country's economic and political clout has not prevented Egypt from casting its vote contrary to that of the US in 83 per cent of issues that came to a vote in the UN (compare this to Israel's record of voting with the US in 87 per cent of the cases). History is full of instances of Egypt's ability to stand firm in the face of US demands. Cairo refused to cooperate with the American attack against Libya in the 1980s and it refused to exert pressure on the Palestinians during the negotiations that took place in the 1990s. Indeed, Egypt, which signed a peace agreement with Israel, has been the foremost obstacle to the rush to normalisation with the Hebrew state, keeping normalisation as a major card in the negotiating process between the Arabs and Israel, in perpetual defiance of Washington's wishes. Nor is it a secret that all the "advice" given by Washington regarding domestic change was not heeded. In fact, those who hold that Egypt is a US dependency would do well to study the entire chapter of the past eight years when Cairo was at constant loggerheads with the Bush administration. Moreover, even then Egypt remained the largest recipient of arms and money from Washington apart from Israel. This was the product of wisdom and skill...Egypt has been playing the US, accepting billions of dollars of aid while not changing its policies towards US interests one iota. All of the benefits of the Egyptian/Israeli peace treaty, as enumerated by the author in the rest of the article, would be just as effective without US largesse.
In other words, all the billions of dollars given by the US to Egypt, ostensibly to influence that country, have gone to waste.
Washington's influence over Israel is not predicated on aid money but on shared interests and a deep friendship. That is what makes a reliable ally. And as we see from this article, Egypt is anything but.