WASHINGTON — The recent leaks about government spying programs have focused attention on the Foreign Intelligence Surveillance Court and its role in deciding how intrusive the government can be in the name of national security. Less mentioned has been the person who has been quietly reshaping the secret court: Chief Justice John G. Roberts Jr.

In making assignments to the court, Chief Justice Roberts, more than his predecessors, has chosen judges with conservative and executive branch backgrounds that critics say make the court more likely to defer to government arguments that domestic spying programs are necessary.

Ten of the court’s 11 judges — all assigned by Chief Justice Roberts — were appointed to the bench by Republican presidents; six once worked for the federal government. Since the chief justice began making assignments in 2005, 86 percent of his choices have been Republican appointees, and 50 percent have been former executive branch officials.

Though the two previous chief justices, Warren E. Burger and William H. Rehnquist, were conservatives like Chief Justice Roberts, their assignments to the surveillance court were more ideologically diverse, according to an analysis by The New York Times of a list of every judge who has served on the court since it was established in 1978.