PARIS — Walls designed to keep people in or out — whether they are in Berlin, Nicosia, Israel or Korea — are always the product of fear: East German leaders' fear of a mass exodus by their citizens seeking freedom and dignity; Greek and Turkish Cypriot leaders' fear of continued war; Israelis' fear of terrorism; or the North Korean leadership's fear of "abandonment" by their martyred people.

To freeze a fragile status quo, to consolidate one's position or to remain separate from others perceived as temptations or threats (or both) — such have always been the goals of politicians who build walls.

Why is there such a difference between the fate of Berlin — now a capital city where the progress of the present is slowly covering the many scars of the past — and the fate of Nicosia, where time has been frozen, or that of Israel, whose "security wall" is expanding like a fresh scar, not to mention the North Korean regime's unlikely consolidation behind its walls of paranoia and oppression?