Judaism is a world wide religion. There are Jews in all continents, including predominantly Muslim countries.
The largest concentrations of Jews are found in Israel and New York, New York, USA.
Their was a time when there were very large Jewish communities in Russia and Eastern Europe. However, during WW II, the Nazis, the fascist Italians, and collaborating Vichy government of France sent 6 million to die in concentration camps. After the war, when Jews tried to return to their former homes, they met with rejection by the remaining Christians. The allies put many of these displaced persons into concentration camps while they deliberated on how to solve "the Jewish problem". Many escaped and immigrated to Palestine under British mandate since WW I. The British limited Jewish Immigration under Arab pressure. The Jewish liberation movement under various factions, waged a war against the British. Eventually the British decided to cut their losses and left Palestine.
At the same time, the UN created a Jewish state and partitioned Palestine between Arabs and Jews. This was 1948. The Jews accepted the UN partition and created the new state of Israel. The Arabs rejected the partition. In a series of aggressive wars, surrounding Arab nations attempted to destroy Israel in 1948, 1967 and 1973. As a result, Israel was victorious and claimed the majority of Palestine: from the Sinai peninisula to the border of Lebanon; from the Mediterranean coast to the Jordan River and the Golan Heights.
There has always been a Jewish presence in Palestine from the destruction of Judea by Rome in 70 CE to the present: especially in the Gallilea.
There were also concentrated communities in Ethiopia, Yemen and Armenia. But after the formation of modern Israel, many immigrated (or were expelled) to Israel.
Moshe David ben Avraham b'eretz Yisra'el
As of mid-2009, adherents of Judaism were found in 135 countries of the world,
and amounted to 0.2% (two tenths of one percent) of world population. They
were a majority of the population in only one country.
Judaism is practiced wherever there are Jews.
As of 2014:
Israel.......... 6,042,000
America....... 5,425,000
France......... 480,000
Canada........ 375,000
United Kingdom 291,000
Russia........ 194,000
Argentina.... 182,300
Germany......119,000
Australia...... 107,500
Brazil........... 95,300
South Africa.. 70,800
Ukraine......... 67,000
Hungary........ 48,600
Mexico.......... 39,400
Belgium........ 30,300
Holland......... 30,000
Italy.............. 28,400
Chile............. 20,500
Other countries, combined: 250,200
Wherever there are Jews. The majority of Israel's population is Jewish; and there are large Jewish communities in America and some Western European countries (especially France and Britain).
Currently or Historically?
Judaism is practiced all over the world, in homes, in synagogues.
Judaism is practiced in the following regions: Israel and major United States cities, and small pockets of North and South America, Europe and Asia.
Judaism is non-stop.
Israel.
Israel.
Jordan is a Muslim nation; Judaism is not practiced there.
Shintoism, Christianity, Judaism, Islam, Hinduism and Buddhism. Shintoism is practiced in Japan, Christianity is practiced throughout the world, Judaism is practiced in Israel and Islam is practiced in the Middle East. Hinduism is practiced in India, and Buddhism is practiced in Southeast Asia as well as China.
Judaism and Christianity.
Christianity and Judaism is practiced mostly in the western world and Islam is mostly practiced in 3rd World Countries
Israel and America.
Christianity and Judaism