According to this editorial in the Washington Post:
… the Catalan nationalists’ only backers are separatist-ruled Scotland, the pariah government of Venezuela and Russia’s intelligence and propaganda apparatus, which mobilized its media outlets and social media bots in support of the separatists. Moscow evidently perceives the Catalan movement as another vehicle for dividing and weakening the democratic West.
Actually, aside from the Dr Strangelove paranoia in this editorial, the Russian stuff might not be so far off the mark. Catalonia is a wealthy region, accounting for some 20% of Spain’s GDP and about one third of its exports. The sanctions tit for tat with Russia over the last three years or so has harmed the EU far more than it’s harmed Russia. Italy, Hungary, Greece, France, Cyprus and Slovakia are among the EU states most skeptical about the sanctions, and although Russian direct investment in Spain is not that high (around $50-60 million per year), Catalonia is the main beneficiary of this trade; that is, before Russia introduced an embargo on agricultural products from the European Union. Catalonia had signed many commercial agreements with various Russian regions, including Lipetsk, Samara, Novosibirsk and Moscow, where Catalonia has recently opened a trade office, despite the sanctions.
If Catalonia does achieve independence it would no longer be in the EU, and even if it wanted to join the EU it wouldn’t be able to. For starters, Spain would veto its membership, and probably a number of other EU countries would do the same. So, independence for Catalonia would mean adios EU, leaving Catalonia free to fully trade with Russia. This is only a small aspect in the independence scheme of things, yet I see it as yet another crack in the rapidly disintegrating American Empire.