Those who bless you I will bless and those who curse you I will curse
--Genesis 12:3, cited by tens of millions of American Christians in their support of Israel
New England Patriots owner Robert Kraft noted an interesting connection between his donation of a football stadium to Jerusalem in 1999 and his team's subsequent dominance of the sport:
Thanks to the generosity of New England Patriots owner Robert Kraft and his wife Myra, American Football is one of the fastest growing sports in the country.
The Kraft Family Stadium, constructed in Jerusalem in 1999, is home to over 1,000 football players in four leagues.
Robert Kraft said, "before building the field in Jerusalem, the Patriots had never won a Super Bowl. Since building the field we have three championships."
Every Patriots game since then has been sold out, including during the preseason.
Of course this isn't proof of a correlation, nor is the study of world history that the Japanese made during World War II which concluded the same thing on a larger scale. The Japanese proposed the immigration of a million Jews after concluding that the rise and fall of nations was based on their treatment of the Jews. Nations that expelled Jews (unfortunately examples were quite plentiful) saw their fortunes plummet. The United States has been by far the most welcoming nation to Jews in history and has also been the most blessed.
Of course, there is a purely rational explanation for this phenomenon. Jews brought ethical monotheism into the world and are thus a Rorshach test of morality. Despots like Hitler, Stalin, Arafat and Ahmadinejad have inexorably immiserated their societies by hating the values that Jews represent.
Update: The Patriots have just completed the first undefeated season in 35 years.