A generation ago, in Berlin, citizens attacked the wall with sledgehammers. Today, in a New Jersey warehouse, conservators are reattaching flakes of paint to the wall with daubs of adhesive so tiny they must be applied by syringe.

It is the strange fate of this 20-foot section of the Berlin Wall, which once separated West from East along the line of Waldemarstrasse, that it should now be found resting horizontally on timber-frame supports, under nearly surgical care.

Even in a vast storeroom, the grotesque faces painted on the wall in the 1980s by the artists Thierry Noir and Kiddy Citny still alarm a viewer with their anger. The graffiti, of course, were only on its western side. No one but security guards could get anywhere near the wall in East Berlin, not across a “death strip” that was fenced, mined, trenched, patrolled by attack dogs and watched from sentry towers.