Poland and the Baltic states are urging the EU to strengthen its eastern borders, warning in a joint letter to Brussels of a “looming threat” from Russia and Belarus. The four EU member countries are trenchant critics of Moscow, which they accuse of orchestrating hybrid attacks including “intimidation, instrumentalization of migrants, sabotage, disinformation, foreign information manipulation and interference.” In their joint letter, seen by AFP on Thursday, the leaders of Poland, Estonia, Latvia and Lithuania urged the bloc to “spend more and coordinate on defense initiatives within the EU an…