1970s: Russia is part of the Soviet Union, which invades Afghanistan.

Today: After the breakup of the Soviet Union, Russia becomes an independent country, which watches as the United States invades Afghanistan.

1970s: San Francisco Opera begins its presentation of annual free concerts in Golden Gate Park. These concerts feature artists from the Opera's season-opening weekend. The event draws some 20,000 listeners.

Today: The San Francisco Opera opens its eighty-third summer season with Russian composer Pyotr Ilyich Tchaikovsky's Queen of Spades, a suspenseful, psychological thriller.

1970s: People in the United States are divided by the Vietnam War. More than 58,000 U.S. soldiers have been killed. Protestors march in the streets by the thousands.

Today: The country is divided over the economy, politics, and the U.S. invasion of Iraq. As of late 2006, nearly three thousand U.S. soldiers have been killed in Iraq and tens...