Well, I'm not the best to explain it properly.
Socialism worked well in small European countries, where there was low crime, a push to succeed, the majority were healthy, high tax rates but many had a decent job, family oriented, with communities sticking together. But I think of it in America, 345 million people, the young getting free higher education, which you know will cause rates to increase. More government, more corruption. Free healthcare in a country where everyone cross country skis and eats fish all day is one thing but where 50% are obese and violence etc, how long can it last? And it always seems to get progressively closer to totalitarianism. And yes, the only answer I hear from socialists is to raise taxes, although cutting the military is often mentioned, which is okay if you're willing to comprimise world power, altho military waste is rampant. So I think the size of a country plays a role. Canada is still fairly small and benefits off some socialist policies, so far.
Sorry, wish I could give you more.