JERUSALEM — Prime Minister Benjamin Netanyahu announced Thursday that his conservative Likud Party would run on a joint ticket with the nationalist Yisrael Beiteinu Party in January elections. The surprise joining of forces immediately shook up Israel’s political map and was apparently intended to cement Netanyahu’s chances of leading the next government.
The move sharpened the contours of the left and right camps in Israeli politics after years during which the major-party leaders, including Netanyahu, had gravitated toward the political center. Political opponents from the center and left warned that the unification of Likud and Yisrael Beiteinu, led by Foreign Minister Avigdor Lieberman, reflected a creeping extremism that would not serve Israel.
By joining, Netanyahu and Lieberman clearly intended to strengthen their tickets and guarantee their leadership of a strong governing coalition in the coming years.
‘‘This joining of forces will give us the strength to defend Israel and the strength to make economic and social changes within the state,’’ said Netanyahu, standing alongside Lieberman at a televised news conference timed to be broadcast live on the evening news programs.
Lieberman, a Russian speaker who immigrated to Israel from Moldova in 1978, is a blunt-talking politician whose party has advocated some contentious and populist policies, like a demand for a loyalty oath in Israel because of concerns about Israel’s Arab citizens.
“We have chosen the option of national responsibility,’’ Lieberman said at the news conference.