Imagine a similar hypothetical entry about Egypt - if you mentioned "independence from UK", then "unification" and then "division" without further clarification, you would confuse readers to no end - not just an ordinary american idi^H^H^Hcitizen, but many other people just do not know about the United Arab Republic! (incidentaly, real article about Egypt mentions just "independence from UK" in the floating table, not the division of UAR).  And I think I understand 'Slovakia' enough, thank you.