STEVEN V. ROBERTS: Pay now or pay later

Mitch McConnell is demonized by Democrats, and rightly so, for his malevolent maneuvering that helped Donald Trump appoint three conservative justices to the Supreme Court. When it comes to policy toward Ukraine, however, the Senate Republican leader has emerged as one of the more courageous and clear-eyed realists in either party.

McConnell is directly confronting the GOP's isolationist wing, asserting during a recent visit to Finland: "It is not an act of charity for the United States and our NATO allies to help supply the Ukrainian people's self-defense. It is a direct investment in our own core national interests.

"If Putin were given a green light to destabilize Europe, invading and killing at will," he added, "the long-term cost to the United States in both dollars and security risks would be astronomically higher than the minuscule fraction of our GDP that we have invested in Ukraine's defense thus far."

That is the right argument at the right time. There is simply no inexpensive way to defend America's "core national interests." The U.S. has already allocated more than $100 billion in economic and military aid for Ukraine, and the bill will continue to rise. But failing to oppose the Russian leader now will be far more costly in the long run, and not only in Europe. Sending a signal of weakness to China could encourage Beijing's imperial ambitions and multiply the strain on our resilience and resources.

The options are clear: Pay the bill now, or pay a lot more later. And that choice is crystallizing at a key inflection point, with both sides preparing for spring offensives aimed at breaking the current stalemate on the battlefield. As the Washington Post put it in a recent editorial, "This is a pivotal moment in 21st-century history and a critical juncture for U.S. interests, leadership and prestige."

This is also a "pivotal moment" for the Republican Party, which is splintering into two factions: pragmatists who grasp McConnell's argument and isolationists who shrink from reality and America's global responsibilities.

There is nothing new about the impulse to place "America First," a phrase embraced by isolationists leading up to World War II and then by Trump as he sabotaged common defense pacts like NATO during his tumultuous presidency.

Today, Republican rivalries are playing out on two fronts, and the first is presidential politics. Trump calls Ukraine a "crazy war" and has been bolstered by a distinct decline in national resolve. Under the headline "Ukraine aid support softens in the U.S.," the Associated Press reports that only 48% of Americans now favor supplying arms to Ukraine, down from 60% a year ago. A Pew survey finds that 26% of Americans now think we give "too much" aid to Kyiv, but that discontent hits 40% among Republicans.

Ron DeSantis, the ambitious governor of Florida, is reading those polls and trying to peel away some of Trump's America First faithful. Some years ago he was bristling with hawkish ardor -- "You're better off dealing with Putin by being strong," he thundered -- but recently he's turned squeamish, telling Fox, "I don't think it's in our interest to be getting into a proxy war with China, getting involved over things like the borderlands or over Crimea."

But other Republican hopefuls are breaking with Trumpian timidity and recognizing the stakes involved. "I would say anyone that thinks that Vladimir Putin will stop at Ukraine is wrong," former Vice President Mike Pence told NBC, adding pointedly, there can be "no room in the leadership of the Republican Party for apologists for Putin."

This split is also emerging on Capitol Hill, where the same hardcore right-wingers who held the House hostage over electing a new speaker are opposing McConnell's pragmatism and future aid efforts to Kyiv. Eleven of them -- led by Rep. Matt Gaetz of Florida -- have unveiled a "Ukraine Fatigue" resolution stating that the U.S. "must end its military and financial aid to Ukraine" and urging the combatants to "reach a peace agreement."

It's hard to image a more misguided approach. The price of freedom is never cheap. Tyrants like Putin can never be appeased, only defeated. Instead of reducing aid to Kyiv, we should be increasing it, bolstering the resolve of the civilian population to withstand the hardships of continued conflict and arming the military with advanced weapons, including fighter jets.

McConnell and the realists are right: Aid to Ukraine is not charity. It's an essential investment in our own national interest.