WASHINGTON — Missile defense supporters, many of whom have been highly critical of U.S. President Barack’s strategy in this area, welcomed the newly unveiled White House plan to expand the existing U.S. territorial shield but described it as a long-overdue course correction.

The centerpiece of the plan, outlined by U.S. Secretary of Defense Chuck Hagel at a March 15 Pentagon press conference, is an increase in the number of ground-based interceptors installed along the U.S. West Coast from the current 30 to 44 by 2017. The $1 billion expansion, prompted in large part by North Korea’s recent satellite launch and nuclear test, effectively reinstates a plan by the administration of former President George W. Bush that Obama scrapped after taking office.

“I strongly support the decision to increase the number of ground based interceptors in our missile defense system,” U.S. Rep. Douglas Lamborn (R-Colo.), co-chairman of the House Missile Defense Caucus, said in a statement issued shortly after Hagel’s announcement. “ … The decision to increase ground based interceptors should be only the first step toward rectifying the cuts in missile defense that the Obama Administration has made in the last four years.”

Lamborn’s comments were typical of many Republicans’ reaction.

During a March 19 event here at the Heritage Foundation, a conservative think tank, missile defense proponents agreed the change was long overdue. The event was held to commemorate the 30th anniversary of U.S. President Ronald Reagan’s Strategic Defense Initiative speech.

“It really is in large measure a return to what we were doing under President Bush,” Henry A. “Trey” Obering, a former director of the Missile Defense Agency, said of Obama’s new strategy.

Sven Kraemer, a longtime defense official and former staff member of the National Security Council, shared a similar, if less generous, sentiment. ”We have plussed up a program that is minimal,” he said.

Kraemer added that even with the administration’s proposed changes, the expansion of the missile shield would not be completed until 2017. Some defense officials believe Iran could achieve the technology to reach the United States with a nuclear weapon as soon as 2015 or earlier.

“Our missile defense hasn’t kept pace,” said Sen. Kelly Ayotte (R-N.H.), a member of the Senate Armed Services Committee.

To help cover the cost of installing the new interceptors at Fort Greely, Alaska, the Obama administration intends to shift resources away from the Standard Missile-3 Block 2B development program, which has already been restructured due to funding shortfalls. Previous White House plans called for installing that interceptor in Poland around 2020 to help protect the United States against an attack from Iran.

Studies have indicated, however, that Standard Missile-3 Block 2B interceptors installed in Poland would not be very effective in protecting U.S. territory. Congress, meanwhile, has been disinclined to fund the new interceptor, forcing the Missile Defense Agency to restructure the effort.

Lamborn nonetheless questioned the administration’s decision to scale back the Block 2B effort, saying it would weaken U.S. efforts to defend itself against Iran.

Ayotte called the move a “concession” to Russian President Vladimir Putin, who has vehemently opposed the installation of U.S. interceptors in Europe as a threat to Russia’s strategic deterrent.

The Standard Missile-3 Block 2B has been the subject of a three-way competition among Boeing, Lockheed Martin and Raytheon.

Doug Graham, vice president of advanced programs in the Strategic and Missile Defense Systems division at Sunnyvale, Calif.-based Lockheed Martin Space Systems, said the corporation’s leaders were disappointed that U.S. defense officials chose to set aside the Block 2B effort.

But Graham, speaking March 21 at a Lockheed Martin event here, said company executives did not view the new direction as a cancellation of the program, but rather a reshuffling. Technology that was being developed for the Block 2B interceptor could resurface in future kill vehicles, he said.

Hagel also said the Defense Department would conduct environmental assessments for another ground-based interceptor site in the United States, as directed by Congress. Officials are investigating three locations, two on the East Coast, which they did not specify, and another at Fort Greely.

Panelists at the Heritage event were quick to say they viewed an East Coast site as very important.

Obering said he would like to see 20 interceptors installed at an East Coast site.

Mike Gruss is a senior staff writer for SpaceNews. He joined the publication in January 2013 to cover military space. Previously, he worked as a reporter and columnist for The Virginian-Pilot in Norfolk, Va. and The Journal Gazette in Fort Wayne, Ind. He...