House Homeland Security Committee Chairman Michael McCaul (R-Texas) raised the specter of "submarine warfare" from Russia while making comments on the downing of Malaysia Airlines Flight 17.
"Mr. Putin is returning to a Cold War mentality," McCaul said. "You said this nationalistic pride [in Russia], a resurgence to regain the glory of the old days … It's not the Al-Qaeda threat, but it's the threat of brute force."
Russia's role in destabilizing eastern Ukraine appeared to culminate last week when Flight 17 went down in territory controlled by separatists with ties to the Kremlin.
Secretary of State John KerryJohn KerryKerry and his dog stroll through women's march Trump fails to mention Clinton in inaugural address Hillary Clinton under microscope at inauguration MORE said Sunday it was "pretty clear" the separatists were responsible with Russian help but he declined to blame the Kremlin for the tragedy.
President Obama has also indirectly tied the crash to Russia.
In contrast, McCaul and Senate Intelligence Committee Chairwoman Dianne FeinsteinDianne FeinsteinJustice requires higher standard than Sessions Senate to vote Friday on Trump's defense picks Senate seeks deal on Trump nominees MORE (D-Calif.) both squarely blamed Putin on Sunday.
"I think Putin is responsible and complicit for what happened," McCaul said.
Lawmakers' growing candor is likely to put pressure on the Obama administration to give more detail on how it plans to counter Russia's actions in the region.