Inconvenient or illegal?

According to these stories from the New York Times and the Washington Times, the US is finding that international assistance to Lebanon (including American) almost always ends up going through the hands of Hezbollah because Hezbollah effectively controls all services in south Lebanon.

Both stories speak about the issue as a political inconvenience. However, if, indeed, it is true that the aid always goes through Hezbollah, the donor countries would appear to be running afoul of the International Convention for the Suppression of the Financing of Terrorism and Security Council resolution 1373.