Russia, the USA and Israel all understand how foreign sales can help defray the cost of weapons system development. For decades Syria deferred procurement of modern weapons systems and a few years back Israel took big advantage of that fact. Syria, as a direct results, procure more modern systems. p.s. Those systems have been substantially improved as a result of the lessons learned from the cyber and electronic warfare methods employed by Israel in September 2007.
High school teacher's union threatens strike (Haaretz)
from the article: Report: Russia signs arms deal with Syria