Britain is not an antisemitic country.
Where do people like you come up with crap like that?. I have read JDL reports that show UK anti-semitic incidents falling as American rates rise. So is your country anti-semitic?.
There are people on FR who are so obsessively and supinely pro-Israeli that any position other than absolute and total unconditional support for Israel and everything they do is perceived and written up as "antisemitic" (and possibly even treasonous). It's the same kind of mentality that sees any objection to Gay Pride week as "homophobia", all criticism of Barack Obama as "racism", and any negative opinion of muslim practices as "Islamaphobia".
I've gotten into arguments over British-Israeli relations with such folk before. It's a waste of time and energy. Britain was stuck with the thankless task of juggling the rival ambitions of Jew and Arab in the Palestine Mandate, and inevitably not every decision went the Isrelis way. To the extreme pro-Israel wing that makes us an enemy. Every decision the British Foreign Office has made since that does not accord with total support for Israel further bolsters that opinion. Selling a weapon system to Saudi Arabia is purely a business transaction, but there is absolutely nothing you can say that will convince them of that. Two centuries from now (assuming the Human race is still going) their spiritual (and probably actual) descendents will be trotting out the same grievances, possibly attached to Biblical injunctions about the terrible consequences of "opposing God's chosen people, the apple of His eye." The fact that there is a divine rider upon the status of Jews as "God's chosen people" will be conveniently never stated, of course.
I humbly suggest it would be a more profitable use of your time to redirect your energies to other threads re Britain and the UK, and let this one go.