I think if you start looking at who has used White Phosphorus grenades in warfare it would be quicker to make a list of who hasn't unfortunately.
That's possibly because the use of white phosphorus in war is legal.
But the Israelis have not simply been accused of "using" white phosphorus.
They have been condemned for firing white phosphorus shells into United Nations compounds and schools in which civilians were sheltering. This is very clearly illegal under international law. Firstly white phosphorus shells must not be used where they might harm civilians, and secondly United Nations compounds must not be targeted.
I would suggest that the list of countries which have used white phosphorus shells illegally, is in fact,
very short indeed.