It’s not easy to leave the mothership, but artists sometimes flourish by venturing away from the familiar. George Harrison’s talent was constrained by the Beatles, who already had two musical geniuses as front men. Harrison’s crowning achievements came after the Beatles split up, topped, in my view, by “All Things Must Pass,” whose lyrics are way too profound to be confined to a broken romance. The same pattern holds for Jason Isbell, who was shown the door by the Drive-By Truckers. Lo and behold, Isbell is way deeper than the DBT’s two accomplished songwriters. I rest my case with “Relatively Easy.”

It’s harder to leave the mothership in politics than in the arts. Political parties cling to shibboleths long past their due dates. Posturing has always accompanied real lawmaking in American politics, but it’s hard to remember a time when there was so much posturing and so little legislating. Republicans on Capitol Hill make the “Do-Nothing Congress” that Harry Truman campaigned against seem hyperactive. Democrats had to figure out how to get past their loathing toward Richard Nixon to re-emerge as an appealing choice to voters. Republicans now face the same challenge with respect to Barack Obama and the Clintons.

Treaties are the mothership of arms controllers, affirming accomplishment and paving the way for next steps. Treaties have helped curtail nuclear proliferation, build down Cold War legacy arsenals, establish monitoring regimes, and nearly abolish chemical and biological weapons. One measure of these accomplishments is the extent to which they enable us to focus on outliers: Without the Nuclear Nonproliferation Treaty, Chemical Weapons Convention, and Biological Weapons Convention, there would be no outliers.

These treaties now have almost universal adherence. They matter greatly even when instruments of enforcement are left to the UN Security Council (NPT), challenge inspections are not invoked (CWC), or when, in the case of the BWC, there are no monitoring provisions whatsoever.

The Senate consented to ratify these treaties in large measure because they imposed restraints on others, not the United States. When the shoe was on the other foot, and constraints fell directly on US strategic programs, the Senate’s consent became far more challenging.

Strategic arms control and reduction treaties were enabled and undercut by deal-making. The practice of securing 67 votes in return for modernizing delivery vehicles and infrastructure began with the Limited Test Ban Treaty. One of the promises made for the LTBT – maintaining readiness to resume atmospheric testing – wasn’t kept. Likewise, not all of the promises made along with the Senate’s consent to ratify New START were kept: nuclear weapon programs are not immune from budget austerity.

Arms controllers now complain that the price of ratification has become way too high. Nuclear deterrence boosters complain about broken promises — especially the promise to build an over-sized facility at Los Alamos for a five-fold increase in plutonium pit production — and how multi-year appropriations can’t be locked down. Deal-making has lost favor.

Besides, no treaty ratification fights are in the offing anytime soon. The Obama administration doesn’t have the stomach or the votes to ratify the Comprehensive Test Ban Treaty. The question on the distant horizon is whether we can learn to live without the entry into force of the next strategic arms reduction treaty.

There’s no need to make decisions in the near term. New START doesn’t expire until 2021, with the possibility of a five year extension. Treaty critics will try to require two-thirds consent to any reductions below New START limits, making the Senate’s consent conditional on a raft of spending commitments. Even then, ratification would be iffy.

The Soviet invasion of Afghanistan put the last nail in the coffin of SALT II ratification. Fast forward to Vladimir Putin. Relations between Washington and Moscow were rocky even before the contest for Ukraine’s future began to play out. It will now take a long time for bilateral relations to get back on track.

Leaving the treaty mothership will be very hard for arms controllers. But the CTBT’s norm against nuclear testing grows stronger with every passing year, and tight Pentagon budgets will result in deeper nuclear force reductions, whether or not there are new treaties. Arms controllers, in other words, don’t need to be supplicants whenever the time comes for future deal making.

Modest reductions are worthy of modest inducements, and no more. But deterrence boosters will demand everything but the kitchen sink, and arms controllers will find it hard to walk away from a deal. Without structure and intrusive monitoring, the “arms control enterprise” will wither alongside the “nuclear enterprise.” Very deep reductions, assuming they can be negotiated over the long haul, are inconceivable unless backed up by treaty-based monitoring.

Ukraine clarifies the obvious – that deal making in return for treaty ratification is an increasingly distant prospect. The longer the standoff between supporters of treaties and nuclear deterrence continues, the more both camps can expect lean years ahead. This impasse doesn’t play well abroad, either. It’s a recipe for trouble when partisans on Capitol Hill alternately deride treaties and nuclear weapons as relics of the Cold War, while friends and potential foes view them as essential.