Though no one imagines that a lasting cease-fire in Gaza will, in itself, produce a substantive breakthrough in the Israel-Palestine conflict, the US and other concerned governments continue to work tirelessly to halt the fighting. Yet, when it comes to the escalating conflict in eastern Ukraine, the relevant external powers – that is, the US, the European Union, and Russia – are not only failing to achieve a cease-fire; they are refusing to pursue a solution that, unlike in the case of Israel and Palestine, is there for the taking.

All that is needed is to introduce into the Ukrainian constitution a provision that significantly impedes membership in any military alliance, whether NATO or the Russia-dominated Collective Security Treaty Organization of the Commonwealth of Independent States. For example, the decision to join such an alliance – or even to implement an agreement that allows a foreign country to base its troops on Ukrainian soil – could require the approval of a qualified majority of, say, two-thirds of voters or regional legislatures.

Introducing such a requirement would amount to granting veto power to Ukraine’s two camps – that is, the country’s more Russia-aligned east and its NATO-leaning west. The practical result – Ukraine remaining unaligned in military and security terms – would reflect the will of the Ukrainian population as a whole.

This approach would be consistent with the principle, which US President Barack Obama highlighted when announcing the latest round of sanctions against Russia last month, that Ukraine must be permitted to "chart its own path.” Above all, it would help the people of Ukraine – divided between inherently antagonistic identities – to live together peacefully.

Of course, Ukraine’s position may change in the future, with cultural, demographic, and economic shifts producing the needed consensus to abandon neutrality. What is important is that the constitution requires a super-majority – rather than, say, the easily reversible "non-bloc” resolution that the Ukrainian parliament adopted in 2010 – to join a military alliance. In such a deeply divided country, joining NATO by a simple majority vote would merely exacerbate unrest, regardless of Russia’s involvement.

Such a solution could also incorporate other, less controversial elements, such as additional powers for eastern Ukraine’s regional authorities, which they could exercise in Russian. Moreover, Russia could be convinced to accept Ukraine’s pursuit of economic integration with the EU, in exchange for cooperative efforts to counter schemes to use Ukraine’s free-trade agreement with the EU as a back door for European goods entering the Russian market.

As it stands, the West is relying on increasingly tough sanctions to persuade Russian President Vladimir Putin to back down, leaving the Ukrainian rebels either to surrender or be crushed – and enabling the Ukrainian government to dictate the terms of the country’s future. Judging from the 14-point peace plan that Ukrainian President Petro Poroshenko proposed in June, the limited concessions that would be offered would not include veto power for eastern Ukraine over the establishment of a military alliance with the US.

For its part, Russia is working to sustain the insurgency because it wants sufficient leverage to ensure Ukrainian neutrality in the inevitable peace talks. Given that Ukraine’s neutrality does not run counter to Russia’s interests, but continued sanctions do, the Kremlin would have no convincing reason to reject an outcome that keeps Ukraine strategically non-aligned, and instead continue supporting the rebels.

To be sure, Putin’s agenda in Ukraine is widely assumed to extend well beyond preventing the country from becoming a base for anti-Russian military forces. If Putin’s goal is annexation or subversion of more Ukrainian territory, he would likely reject the solution, even if Ukraine (perhaps reluctantly) supported it.

But it would be irrational to reject a solution with the potential to save so many lives based on an unsubstantiated assumption. Only by proposing its deal to Russia’s government – as well as to the rebel groups in eastern Ukraine – can its stance be known.

In fact, there is plenty of reason to believe that Putin would be satisfied if Ukraine remained intact, as long as it did not join NATO and respected eastern Ukrainians’ Russian identity. Most important, from Russia’s perspective, the competition with the EU over Ukraine’s trading alignment is trivial compared to the imperative of keeping NATO – that is, the US military – out of the country.

In the Ukrainian crisis, unlike in the Israel-Palestine conflict, negotiators do not have to settle for flimsy agreements – intended to save as many lives as possible in the short run – at the expense of important principles and long-run peace prospects. Policymakers have an option that addresses the root cause of the crisis, at once upholding Ukrainian sovereignty and assuaging Russia’s strategic insecurity. They should pursue it.

The witer is a former British diplomat in Moscow.