The U.S. commander of NATO declined to predict Wednesday how Russian President Vladimir Putin would react to the U.S. sending weapons to Ukraine but added that even with American weapons, Ukraine forces could not prevent a Russian invasion.
"Clearly we don't know what Mr. Putin will do," said Air Force Gen. Philip Breedlove, who doubles as NATO's supreme allied commander and the head of U.S. European Command.
"It could cause positive results, it could cause negative results," Breedlove said of proposals being considered by the Obama administration to provide Ukraine with defensive weapons. "What we are doing now is not changing the results on the ground."
New Defense Secretary Ashton Carter has said he was "inclined" to support arming the Ukrainians, but Breedlove said that even with defensive weapons the forces of the central Kiev government would still be no match for the Russian-backed separatists in eastern Ukraine.
"I do not believe Ukrainian forces can stop a Russian advance in Eastern Ukraine," Breedlove said in testimony to the House Armed Services Committee (HASC), adding that a way must be found to raise the "cost-calculus" for Putin's continuing aggression.
At one point, Breedlove appeared to agree with the suggestion of Rep. Mike Rogers, R-Ala., that Putin would only be deterred by mounting Russian casualties.
"You're talking about body bags," Rogers said of Breedlove's comments on raising the costs for Putin. Breedlove paused briefly and responded: "I think we should talk about raising the costs in many dimensions."
Christine Wormuth, the defense undersecretary for policy who testified alongside Breedlove, said "there is discussion on providing defensive lethal assistance" to Ukraine that is ongoing within the Pentagon and the White House, but she warned of the risks.
"The potential concern has to be weighed – does Russia double down" in backing the separatists and in seeking to foment unrest elsewhere in Europe, Wormuth said. However, Wormuth said "we will again look at measures to impose additional costs" beyond the current economic sanctions.
Rep. Mac Thornberry, R-Tex., the HASC chairman who has backed a bill to arm Ukraine, said "we know how [Putin] has responded without us providing weapons, and that hasn't gone very well."
Breedlove was adamant in asserting that Russian troops were present in eastern Ukraine and were supplying the separatists with artillery, command and control guidance and more than 1,000 pieces of heavy equipment to include tanks and armored personnel carriers.
Breedlove said the Ukrainians have provided him with a "consistent picture" of what they wanted in the way of arms, and "I have advised my chain of command" of the list.
The U.S. has been delaying a decision on supplying arms to Ukraine while gauging whether a ceasefire agreement promoted by Germany and France earlier this month will hold despite rebel advances that drove Ukrainian forces from the rail hub town of Debaltseve.
While the U.S. weighs a decision, Ukrainian President Petro Poroshenko was in the United Arab Emirates at the International Defense Exhibition and Conference where he claimed to be working on a deal to buy defensive weapons from the UAE, the Wall St. Journal reported.
-- Richard Sisk can be reached at richard.sisk@military.com