Germany and France have launched a direct high-speed train between Berlin and Paris. The new connection was hailed Monday as a symbol of the two countries’ close friendship and a sign of Europe’s potential to attract more travelers to the rails — but it is unlikely to be a game-changer. At about eight hours, the once-per-day service between the two capitals with German operator Deutsche Bahn’s ICE trains offers an increase in convenience rather than any major time saving compared with other, indirect connections.