The most recent incident took place in the 2016 Rio Olympics during the men's heavyweight judo bout between Or Sasson of Israel and Egyptian judoka El Shehaby. After the match, which Sasson won, Shehaby spurned a handshake extended by Sasson. Another similar incident occurred in Rio when a Saudi judoka quit because there was a chance that she could have faced Gili Cohen, an Israeli. The opening day ceremony sparked controversy when the Lebanese delegation refused to travel in the same bus as Israeli athletes.
Russia's engagement in Syria can be divided into roughly two phases-- (a) Playing the role of a mediator (2011-2015) and (b) Engaging in direct overt action (2015 onwards). Moscow, since the beginning of the conflict, has been critical of the US position regarding Bashar al-Assad and has opposed almost every US-backed initiative in Syria. For Russia, Syria is its strongest Middle Eastern ally and losing is just not feasible.