Democrats and Republicans agree that the nation’s missile defenses — designed to blunt missile threats from North Korea and Iran — need improvement.

But while the House wants to buy a new missile that has failed a recent test and commit to building an East Coast missile defense site, which would use an incomplete upgraded version of the missile, some key Senate leaders are far more skeptical.

Top defense policy and spending Democrats in the Senate said last week they would oppose efforts to go beyond what the administration has sought for upgrades to the ground-based interceptor, a missile used by the Ground-based Midcourse Defense system, and an East Coast missile site, despite provisions in the House defense authorization and spending bills seeking to do just that.

The conflict is one in a long line of missile defense disagreements between the two parties over the years. But it comes as the Defense Department tries to identify its priorities in an unstable fiscal environment and Congress grapples with a long series of purchases that went awry because the military, with congressional support, bought weapons that had not completed sufficient testing.

“Before we go forward on missile defense we need a successful test, period,” said Richard J. Durbin, D-Ill., chairman of the Senate Defense Appropriations Subcommittee. “Before we expand the missile defense layout to include the East Coast, we need a pretty fulsome debate after a successful test.”

The discussion foreshadows tough debates on the Senate floor when the chamber takes up its version of the fiscal 2014 Defense policy (S 1197) and appropriations bills later this year.

The Senate Defense Appropriations Subcommittee marked up its spending bill Tuesday, with the full committee scheduled to take up the bill Thursday.

Self-Fulfilling Prophecies

Several Republicans, including Rep. Trent Franks, R-Ariz., made the case on the House floor last week that budget cuts to the Missile Defense Agency may have actually contributed to the test failures, the latest of which occurred July 5, when the missile didn’t separate from its booster and failed to engage its target in what is already a highly controlled testing environment.

“One nuclear armed missile coming into the United States could ruin our whole day,” Franks said. The president and Democrats “criticize these programs when there are test failures or delays that have been made worse by their slashing and burning of the program. … While the Ground-based Midcourse Defense system did miss its target on a July 5 test, it was one test.”

The House last week passed a spending bill (HR 2397) that would add about $107 million to the president’s spending request for 14 upgraded missiles, after defeating an amendment that would have stripped out the money. The president recently outlined plans to add 14 more missiles to a launch site in Alaska after a recent missile test by North Korea.

Rep. Jared Polis, D-Colo., noted that the ground-based missile defense program, writ large, has not had a successful intercept since December 2008.

“These repeated failures unfortunately have not stopped us from continuing to authorize” funds for “14 additional missiles on top of the 30 we already have in the” fiscal 2013 defense policy law (PL 113-239), Polis said.

Despite Government Accountability Office findings that there has been insufficient testing to verify whether the system will work as intended, the military’s top missile defense officer, Vice Adm. James D. Syring, told Durbin during a July 17 hearing, “We stand by the results we have obtained” from the new missile interceptor tests to date.

But Syring, the director of the Missile Defense Agency, acknowledged the problems of the missile defense program overall, suggesting it was rushed in the face of growing signs of missile threats from North Korea and Iran, with the intent of developing and fixing system shortfalls on the fly. He also said he thought it would be best to see successful tests before committing to the purchase of 14 new interceptors.

Syring acknowledged that the system has never been tested against an intercontinental ballistic missile of the kind that would reach U.S. shores, but he assured Durbin he believed the United States was well defended.

When Durbin expressed doubts about this conclusion, Syring said, “We have extensive model and simulation capability that projects the results of our conducted intercept testing in the longer range environment.”

The military won’t, however, have a test target to verify these simulations until 2015, he said.

Debating an East Coast Site

Rep. Michael R. Turner, R-Ohio, a senior member of the House Armed Services Committee, helped kick-start the push in Congress to build an East Coast missile defense site to supplement defenses in Alaska and California. He helped defeat an amendment offered by Rep. Jerrold Nadler, D-N.Y., that would have stripped out $70 million set aside in the Defense spending bill for the East Coast site, even though Syring has asserted there is not yet a “validated military requirement to deploy an East Coast missile defense site.”

Several Senate Democrats made the case last week that Republicans have often been too willing to buy systems before proper testing is completed at great cost to taxpayers.

Sen. John McCain, R-Ariz., who has argued for feasibility studies of an East Coast site before a larger commitment, also said that hearings must be held to assess the recent test failure before Congress makes a larger commitment.

Sen. Carl Levin, D-Mich., chairman of the Armed Services Committee, said he’s for “flying before buying.” But he said he expects his Republican colleagues to make an effort on the Senate floor to push for buying the 14 upgraded missiles for the site in Alaska and moving forward with the East Coast missile site.

“It just shows you, [Republicans] are ready to expand a program that has not had a successful test,” Durbin said. “I think we owe it to the taxpayers to say we want a country that is safe. We want a system that works. We want a test that proves it.”