Sen. Mark Kirk is blocking President Barack Obama's nominee to become ambassador to Russia over suspicions the U.S. might provide Moscow with sensitive missile defense information.
The White House says it won't provide such data, and that Kirk's stipulations are so broad, they would harm collaboration.
Kirk's block of Michael McFaul, a senior adviser to the president, puts the Obama administration in a difficult situation with Russia.
According to the Associate Press:
It also has political overtones ahead of next year's elections. The White House considers improved relations with Russia, including the signing of a major arms reduction treaty, to be one of the big foreign policy successes of Obama's presidency. Republicans have accused Obama of granting too many concessions to Russia and getting little in return.
Kirk is holding up the nomination of Michael McFaul, a senior adviser to Obama on Russia. In an interview with The Associated Press, Kirk said he wants written assurances that the United States will not provide Russia with any currently classified information on the missile defense system.
"In the future, some classified information exchange may benefit the United States," White House spokesman Tommy Vietor said in a statement.
U.S. missile defense plans in Europe have been one of the touchiest subjects in U.S.-Russian relations going back to the administration of Obama's predecessor, George W. Bush.
One of Obama's earliest moves to ease tensions was the administration's 2009 announcement that it would revamp Bush's plan to emphasize shorter-range interceptors. Russia initially welcomed that move, but has more recently suggested that the new interceptors could threaten its missiles as the U.S. interceptors are upgraded.
U.S. talks with Russia over missile defense cooperation have nearly broken down. Russia recently threatened to target missiles at the U.S. missile defense systems in Europe and just commissioned a radar in Kaliningrad, near the Polish border, capable of monitoring missile launches from Europe and the North Atlantic.
Kirk, a naval intelligence officer and a Senator, often takes opportunities to burnish his foreign policy credentials.
Earlier this year, Kirk traveled to Libya as part of the first official convoy of American legislators.