Bob Gates has worked in senior national security positions for the last five presidents, Republican and democratic. So it’s noteworthy -- and to me, encouraging -- that he is advising President-elect Donald Trump, too.

Gates, a former defense secretary, CIA director and deputy national security adviser, spoke with me by telephone Wednesday about the advice he’s giving Trump and his team -- and the opportunities and pitfalls ahead.

At the top of Gates’ to-do list is striking the right balance between improving relations with Russia and appearing too cooperative with a belligerent President Vladimir Putin.

“I think the challenge for any new administration would have been how to thread the needle -- between stopping the downward spiral in US-Russian relations, which had real dangers, and pushing back on Putin’s aggressiveness and general thuggery,” Gates explained.

“If you only want to stop the downward spiral, you empower Putin to feel that he can do whatever he wants. I worry that if you don’t have pushback -- let him know there are limits, and that the US will react, militarily, if necessary -- then the chance of being taken advantage of is larger.”

Gates explained that if he had been secretary of defense when Russian jets made “dangerously close passes” over US warships in the Baltic Sea in April, “I’d have recommended that we send a message to Moscow that the next time you do it, I’ll ‘paint’ you (with targeting radar), and I may shoot.”

If Trump is seen as too eager to cooperate with Russia, Gates cautioned, it will create perceptions in Europe, China, North Korea and Iran that “this guy isn’t prepared to back up his words with the tough action that’s necessary.”

Trump made a surprising, and somewhat ominous, pushback against Moscow on Thursday. After Putin said he planned to “strengthen the military potential of strategic nuclear forces,” Trump tweeted, “The United States must greatly strengthen and expand its nuclear capability until such time as the world comes to its senses regarding nukes.”

Gates told me Thursday that he wished Trump had used the word “modernize,” rather than “expand,” but that “what he said is OK given Putin’s recent comments.”

Gates has shared the role of informal counsellor to the Trump transition team with two other veterans of the Bush administration, former Secretary of State Condoleezza Rice, who talks regularly with Vice President-elect Mike Pence, and former national security adviser Stephen Hadley. The three have a consulting firm, RiceHadleyGates, which has proposed candidates for cabinet and sub-cabinet jobs, including recommendations of Rex Tillerson and retired Gen. James Mattis, the choices for secretaries of state and defense, respectively.

Gates, Hadley and Rice have also talked with foreign governments that are puzzled about how to approach Trump. In an interview this week, Hadley summarized his basic advice, “We’ve never had a populist movement or political insurgency quite like this -- that actually captured the White House. That means there will be more discontinuities in our foreign policy. I’m telling people, ‘Give us some space here and have some strategic patience. And don’t overreact -- even to Trump’s tweets.’”

One issue that worries Gates is the multiplicity of people surrounding Trump in the White House, seeking to influence an undisciplined chief executive. “What happens when someone tries to get in to see the president with a proposal or initiative and is rebuffed by one gatekeeper -- and simply goes through another door? It’s a formula for a disjointed process.”

“There will be a rough break-in period,” predicted Gates. Part of the challenge is that Trump believes his success stems from his freewheeling, undisciplined style and personal messaging through Twitter -- which makes him resist limits.

Gates credits Trump for choosing strong personalities for the key national security posts: Tillerson, Mattis and retired Gen. John Kelly at Homeland Security. “He’s willing to surround himself with very strong figures who ... will tell the president what he needs to hear.”

Trump’s insurgent, populist style has worried many foreign governments. But Gates argues that “there is some value in a disruptive approach -- in the US not being so reliably passive” in responding to events as it seemed during the Obama administration.

Trump, by accident or design, has created a hint of the triangular dynamic among the US, Russia and China that was a hallmark of Richard Nixon and Henry Kissinger’s diplomacy. Ideally, said Gates, the US could play off Russia and China so “they’re both uncertain about where we’re headed.”

But this subtle play requires a strategic vision and disciplined follow-through -- two qualities that Trump has yet to demonstrate.

By DAVID IGNATIUS

David Ignatius’ email address is davidignatius@washpost.com. -- Ed.

(Washington Post Writers Group)