By some accounts, Russia and the United States are on the brink of a new Cold War. That probably overstates the state of that bilateral relationship, but there is no mistaking the chill that dominates relations between the two countries. In an attempt to end the downward spiral, U.S. President George W. Bush hosted Russian President Vladimir Putin at his family home in Kennebunkport, Maine, for fishing and a lobster summit. The hospitality did not end the rancor, but it has provided an opportunity for the two men to resume cooperation.

Relations between Russia and the U.S. have worsened since Mr. Bush looked into the soul of Mr. Putin in Llubljana, Slovenia, in 2001 and saw a man with whom he could do business. The two men have disagreed over just about every major foreign-policy issue: Iraq, Iran, North Korea, NATO expansion and Kosovo are just the most glaring differences. Russians feel increasingly slighted: Their offer of partnership has been spurned while the U.S. makes decisions that damage Russian national interests. Many Americans see Moscow as ready to oppose the U.S. for opposition's sake and prepared to back unsavory regimes even if such actions undermine international norms. Mr. Putin, empowered by surging oil revenues, is eager to flex his international muscle and reassert Russia's claim to great power status.

Mr. Putin's language has been increasingly brusque. Several months ago, he likened the U.S. to Hitler's government and called it a threat to world peace. His bete noir these days is the U.S. plan to install a missile defense system with some 10 interceptors in Poland and the Czech Republic. Despite U.S. assurances that this program is aimed at protecting against attacks from Iran and poses no threat to Russia's huge missile arsenal, Russian officials have condemned the proposal, threatened to target missiles at countries that host the facilities, and to move missiles as far west as possible.