Arms control has boom-and-bust cycles. We’re now going through very tough times. They remind me of the Carter administration. As Yogi Berra has said, it feels like déjà vu all over again – only Obama’s challenges are more severe. This time, instead of a sclerotic Kremlin leadership bungling into Afghanistan – the graveyard of great power follies – Obama faces a brazen Kremlin leader who seeks to upend the post-Cold War order on NATO’s doorstep.

In tough times, it’s good to remember this timeline: eight years after the Soviet invasion of Afghanistan, Ronald Reagan and Mikhail Gorbachev signed the INF Treaty. I don’t expect another reversal of this magnitude in my lifetime, but I do expect U.S.-Russian relations to stabilize eventually. The challenge now is to respond effectively to adversity, to reassure friends and allies, to minimize losses, and to position ourselves for future gains.

President Carter was as committed to reducing nuclear dangers as President Obama. In both cases, their ambitions were whittled down by domestic constraints and a deteriorating international environment. In my view, Carter was more ambitious than Obama. This is what he said about a world without nuclear weapons in his inaugural address:

The world is still engaged in a massive armaments race designed to ensure continuing equivalent strength among potential adversaries. We pledge perseverance and wisdom in our efforts to limit the world’s armaments to those necessary for each nation’s own domestic safety. And we will move this year a step toward our ultimate goal–the elimination of all nuclear weapons from this Earth. We urge all other people to join us, for success can mean life instead of death.

Carter tried to cap the strategic arms race, sought to negotiate a comprehensive test ban and pursued arms control in space. Obama has offered only passing references to ratifying the CTBT and contracted out an international code of conduct for space to the European Union.

Obama spoke eloquently about a world without nuclear weapons in Prague, with the appropriate caveats. He then focused on securing a verifiable regime for deeper strategic arms reductions. Carter convinced the Senate to consent to the ratification of the Panama Canal treaties and was then stymied on SALT II. Obama managed ratification of New START, after which he was caught between the rock of Vladimir Putin and the hard place of Senate Republicans.

Both Presidents were confronted with the Kremlin’s use of force across international borders. Carter began the program of covert assistance to the “mujahedeen,” which was ramped up considerably during the Reagan administration. Obama is now contemplating what more is needed to help the Government of Ukraine.

Obama’s strategic instincts are to clean up inherited messes, to not swing for the fences in complex circumstances, to settle for singles and doubles, and above all, to avoid stupid, costly mistakes. Obama’s caution abroad — with the exception of a risky decision to employ Special Forces in Pakistan to hunt down Osama bin Laden — is understandable after a presidency of painfully excessive reactions. But an excess of caution when negative events snowball turns virtue into liability. Obama is now faced with hard choices as his batting average drops.

According to William Manchester, President John F. Kennedy sent 400 Green Berets to South Vietnam after telling his inner circle, “We have a problem making our power credible and Vietnam looks like the place.” Obama now has to decide how to make U.S. power credible in Ukraine and elsewhere around Russia’s periphery, as well as in the Middle East, without making a mistake like JFK’s.

Of those who now question Obama’s steel, the most important are Vladimir Putin and Xi Jinping. Just as Nikita Khrushchev took the measure of JFK at Vienna in 1961 and discerned a President who could be pushed around, Putin seems to have concluded that the door is open to carving out a protectorate for Russian-speaking people, real and imagined, in southeastern Ukraine. In my view, Ukraine deserves more help than tougher sanctions to counter Putin’s moves. Xi Jinping will be watching this high-stakes contest to figure out his next steps in the South and East China seas. China, like Russia and the United States, is also ramping up its military capabilities in space.

Arms control always rides in the back seat of geopolitics. A strenuous response to Putin’s adventurism will have negative repercussions on arms control for the near term. The absence of a strenuous response will have negative repercussions over the long haul. Successful outcomes depend on cooperation among major powers and U.S. leadership which, in turn, depends on bipartisan support and a willingness to take risks. Leadership without followership leads nowhere; followership is coaxed by leveraging others to make stabilizing choices and dissuading them from dangerous ones. The Obama administration has not had the benefit of bipartisan support and hasn’t done well in leveraging desired outcomes.

Large geopolitical challenges are but the leading edge of systemic weaknesses in the nuclear order. U.S. leadership at the 2015 NPT Review Conference has been harmed because Senate Republicans, in their obduracy in all things hinting of arms control, have yet to confirm the U.S. Ambassador. Avoiding further damage depends on enough stakeholders having the wisdom not to rock a boat that is leaking. The process of strategic arms reduction will probably be stalled for longer than advocates care to admit, and the pursuit of abolition at a time when major powers are either at loggerheads or testing each other becomes surrealistic.

Other regional crucibles are heating up. The young leader of North Korea is ambitious and seems to be disregarding Beijing’s messages. A nuclear deal with Iran could be losing ground to patchwork fixes. The prelims are underway for another nuclear-tinged crisis on the subcontinent, even as Pakistan’s civilian government faces extraordinary challenges. Secretary of State John Kerry has his hands full and Obama is without persuasive emissaries to deal with new crises.

Under these circumstances, preserving as much as possible of the arms control infrastructure becomes a sound baseline strategy. I’ve written previously about moving forward with provisional application of the CTBT’s monitoring regime while awaiting entry into force. Time can be well spent trying to forge norms with China for responsible behavior in space and at sea. And as President Obama shores up Ukraine and reassures friends and allies, he would be wise to bring new firefighters aboard who have standing on both sides of the aisle.