This has not been reported in the pro Israeli British media yet but apparently, the British government according to leaked audio tapes has been getting legal advice from it's lawyers for some time telling them that what Israel is doing is (in their opinion) unlawful and if they continue to supply weapons to Israel, they could be deemed complicit in Israel's war crimes. our so called pro Israeli Government chose to ignore this advice.
It is if your neighbour is in dispute with another neighbour and you supply him or her with stones to throw through their window, you are complicit in that crime.
It is if your neighbour is in dispute with another neighbour and you supply him or her with stones to throw through their window, you are complicit in that crime.