A group of pro-defense Republicans is blaming President Barack Obama’s missile-defense budget cuts for contributing to the failure of a recent missile-interceptor test.

A Ground-based Interceptor launched from Vandenberg AFB in California failed to hit a long-range ballistic-missile target over the Pacific Ocean on July 5. The previous two tests of the interceptor, currently used in Alaska and California, also failed.

“While it may take some time to reach a final diagnosis of the cause of the July 5th test failure, it is already clear that President Obama’s decision to drastically cut funding for the GMD program since he came to office and to ‘curtail additional GMD development,’ has drained funding available to conduct needed tests of the system,” the GOP lawmakers wrote to Defense Secretary Chuck Hagel on Friday.

PentagonSenate Armed Services Committee Ranking Member James Inhofe (R-Okla.), Strategic Forces subcommittee Ranking Member Jeff Sessions (R-Ala.), House Armed Services Committee Chairman Howard “Buck” McKeon (R-Calif.), and Strategic Forces subcommittee Chairman Mike Rogers (R-Ala.) lamented in the letter that since the last successful test, in December 2008, there have been only three attempted intercept tests and two flight tests.

And, they pointed out, funding for the Ground-based Midcourse Defense (GMD) system–which is intended to protect the United States from incoming missiles–was cut by nearly half from 2008 to 2012, from a high of $2 billion.

Inhofe, Sessions, McKeon, and Rogers called on Hagel to support building a next-generation kill vehicle for the GBI.

“Regardless of the causes of the recent flight test failures, we encourage you to make the development and deployment of a new kill vehicle one of your highest priorities,” they wrote, noting his recent decision to deploy the 14 additional GBIs in Alaska to counter the threat from North Korea. They also called for the Pentagon’s Missile Defense Agency to conduct a new intercept test as soon as possible of the CE-1 Enhanced Kill Vehicle GBI.

“We believe such a test should occur in 2013 to ensure there is no question about the capability and credibility of the GMD system–our only national missile defense capability,” they said.

The four lawmakers requested the MDA craft “an action plan to resolve the cause of the failure of the recent missile defense test, conduct a new intercept test of that system, and…provide a clear roadmap for the development and fielding of a next generation kill vehicle for the GMD system that will be required to stay ahead of the long-range ballistic missile threats to the United States.”