WASHINGTON - Retired US Army Gen. David Petraeus warned lawmakers the weakening of NATO and the European Union plays into the hands of Russian President Vladimir Putin's attempts to undermine liberal democracies.

"I would argue that repulsing this challenge is as much a test of America's faith in our best traditions and values as it is of our military strength, though our military strength obviously is a crucial component of our national power and does need shoring up," Petraeus said Wednesday.

Petraeus, the former CIA director, appeared before the House Armed Services Committee with John McLaughlin, the former CIA deputy director. Petraeus warned that "revisionist" powers Russia, China and Iran are seeking to weaken the rules-based international order that emerged after World War II just as the US faces "a loss of self-confidence, resolve, and strategic clarity" about saving it from collapse.

"This is precisely what some of our adversaries seek to encourage," Petraeus said. "President Putin, for instance, understands that while conventional aggression may occasionally enable Russia to grab a bit of land on its periphery, the real center of gravity is the political will of the major democratic powers to defend Euro-Atlantic institutions like NATO and the EU."

Some 3,500 US troops have been deployed as part of troop rotations to Europe. NATO will also deploy four battalions to its eastern flank later this year, one each to Poland and the three Baltic states, the Associated Press reports.

Petraeus said he was heartened by the deployments and Defense Secretary Jim Mattis' calls to reassure allies, but he criticized the previous administration for wavering on sending Ukraine shoulder-fired antitank missiles.

"You're not going to run to Moscow with these," Petraeus said, referring to the weapons in a hypothetical offensive scenario. "Yet we did not send these to Ukrainian forces fighting Russian-backed separatists. We should be careful: Firmness should not bleed into provocation."

Petraeus and McLaughlin praised Mattis for an upcoming trip to Japan and South Korea meant to reassure Pacific Rim allies. Trump has backtracked in recent days from remarks questioning the security alliance with Japan, but he has formalized the US withdrawal from the Trans-Pacific Partnership trade pact.

Amid pointed questions from California Democrat Jackie Speier, Petraeus noted that NATO allies have begun to contribute more to their defense since to Trump criticized the lopsided arrangement.

Otherwise, the remarks amount to an indirect rebuke of Trump, who has questioned the NATO alliance, pledged an "America First" approach to foreign policy, and won in an election targeted by a Russian influence campaign.

Nearly two months ago, Petraeus met with President Trump and was then a contender for the secretary of state nomination that eventually went to Exxon CEO Rex Tillerson. 

Amid questions about a rapidly executed and hotly controversial travel ban signed by President Trump at the Pentagon last Friday, Petraeus and McLaughlin warned against alienating Muslim allies in the fight against the Islamic State.  Petraeus did not dispute the need for the order, however.

Critics have claimed the ban, which targets some Muslim-majority countries, fuels Islamic State propaganda premised on the idea that there is a clash of civilizations between the West and Islam. To boot, members of Congress have pressed for the order to be overturned or exempt interpreters who've worked with US forces in the past.

The travel ban includes a 90-day halt on any travel into the United States by citizens of Iraq, Syria, Iran, Sudan, Libya, Somalia and Yemen, and a 120-day suspension of the US refugee program.

Under the terms, Gen. Talib al-Kenani, commander of Iraq's counterterrorism forces, can't meet in person with officers from the US-based US Central Command, which overseas operations in the Mideast, according to Petraeus. 

Petraeus also said al-Kenani's family lives in the United States because of threats they face in Iraq. 

Amid questions from Massachusetts Democrat Rep. Seth Moulton, who served under Petraeus in Iraq, the retired four-star called for "clarifications and exemptions," plus steps to weed out terrorists and reassurances to Muslim allies that the travel ban is only temporary. 

"It's always worth testing a policy by whether it will take more bad guys off the street than it creates, and this is a case if you had done the kind of staffing that perhaps might have been done, you would have found that earlier on," Petraeus said.

McLaughlin, echoing Petraeus, said the administration should have thoroughly vetted the US visa policy and its implementation internally.

"I would like to think an administration learns these lessons, but we have to see," McLaughlin said.

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