At the NATO summit in Madrid, Finland was invited to join the alliance. What does this mean for Finland? If Russian President Vladimir Putin breaches the 830-mile Finnish border, the United States will rise to Helsinki's defense and fight Russia on Finland's side. What does Finland's membership in NATO mean for America? If Putin makes a military move into Finland, the U.S. will go to war against the world's largest nation with an arsenal of between 4,500 and 6,000 battlefield and strategic nuclear weapons. No Cold War president would have dreamed of making such a commitment -- to risk the...