Last week, at NATO’s 75th anniversary summit in Washington D.C., the United States and its NATO partners agreed to support Ukraine “on its irreversible path to full Euro-Atlantic integration, including NATO membership.” President Joe Biden also announced the “Ukrainian Compact” and promised that any future Russian armed attack on Kyiv would be met with “the provision of swift and sustained security assistance and the imposition of economic and other costs on Russia.”
The path to Ukraine’s membership of NATO remains long and winding, but the summit underscored the remarkable degree of Western backing for Kyiv over the last two years. Since 2022, the United States alone has sent over $100 billion in aid to Ukraine. Despite pushback from Donald Trump and the populist right, bipartisan majorities in Congress have consistently backed support for Kyiv. In April 2024, Congress approved a $61 billion aid package with a majority of 311 to 112 in the House and 79 to 18 in the Senate. Why has the United States shown such strong support? Aiding Ukraine is a deeply moral cause, and it also serves US national interests. But there is also a hidden—and brutal—strategic logic for sending assistance. No one talks about it, and yet Machiavelli might offer an approving smile.
The Biden administration cast US aid to Ukraine in starkly moral terms. In 2023, the president said: “Faced with a threat to the peace and stability of the world, to democratic values we hold dear, to freedom itself, we did what we always do: The United States stepped up.” The ethical rights and wrongs in global politics are often murky—but not in this case. In 2022, authoritarian Russia launched an unprovoked invasion of its democratic neighbor, attempted to annex territory, and engaged in systematic war crimes. In 2023, the International Criminal Court issued an arrest warrant for: “Mr Vladimir Vladimirovich Putin, born on 7 October 1952, President of the Russian Federation.”
As well as the moral stakes, there is also a compelling case for aiding Ukraine based on US national interests. Russian aggression threatens NATO territory, encourages Moscow to align with rogue actors like North Korea, and could even embolden China to attack Taiwan. The 2022 US National Security Strategy described how: “Russia now poses an immediate and persistent threat to international peace and stability.”
In global politics, American values and interests rarely line up so neatly. Sometimes, there is a moral imperative to act but few compelling interests at stake, like stopping genocides in Rwanda or Sudan. Other times, US interests might favor a policy that is ethically dubious, like the mass bombing of Germany and Japan in World War II. Ukraine is different. There is a powerful reason to act based on ethics and interests.
Moreover, there is a deeper—and more secret—rationale for the United States to help Ukraine: brutal Realpolitik. Let us take a step back and imagine a highly simplified world of ruthless geopolitics, almost like a game of Risk. In this world, countries compete incessantly. Politics is coercive and utterly cold blooded. There is no room for moral considerations. This world is driven by the law of power, not the power of law. Now imagine that in this world there are two great powers, A and B, each plotting to defeat the other.
How might A defeat B? Of course, A could launch a direct war against B, but this might be extremely costly. A smarter strategy would be for A to weaken B internally, for example, by inciting civil war, state collapse, or secession. Let us assume that this works and B splits apart into two states: B (the remaining rump state) and C (a new smaller country that seceded from B).
If you are A, the world already looks a whole lot better. Your main rival is weaker, and you can divide and rule. But Machiavelli would not stop now. The next step is to provoke B and C to fight each other, which will weaken B even more.
And then we are ready for the coup de grace. A should aid whichever side in the war is weaker—in this case C. Just to be clear, A is not trying to help a plucky David resist the mighty Goliath. Rather, the aim is to stop B from defeating C, absorbing its neighbor, and becoming a peer competitor once again.
At this point, we might expect A to play its hand carefully. Ideally, A would not get dragged into the war between B and C. It would just let them pummel each other. A quick loss for B is fine, but B might lick its wounds and recover. The best outcome is a prolonged war, where B gets bogged down in a quagmire, and is too exhausted to resist A.
It is undeniably a grim vision of global politics. Do states actually behave this way in the real world? One example of this kind of logic is the American Civil War. In 1861, A was Britain and B was the United States. The United States (B) suddenly collapsed into civil war and a new actor emerged, the Confederacy (C). Some British officials were tempted to back the Confederacy based on Realpolitik logic. After all, the United States was getting too big for its boots. But in the end, London stepped back from the brink, partly because the Union won battlefield victories and partly because of moral concerns about slavery.
Another example where hints of this logic are present is the United States and China. In 1949, China effectively split into two: the Communist mainland and non-Communist Taiwan. Just as Realpolitik logic would predict, the United States supported the weaker part, Taiwan. Beijing certainly suspects that ruthless reasoning guides American thinking, and Washington seeks to keep China divided and weak. When the United States and China normalized relations in the 1970s, Washington “acknowledged” Beijing’s position that Taiwan is part of China, but refused to recognize China’s sovereignty over Taiwan, despite Beijing’s repeated demands. As strategic competition between the United States and China escalated, the US position on Taiwan has also toughened. In 2022, Biden signaled that US forces would defend Taiwan in the event of a Chinese invasion, and it is not just Taiwan. At times, the United States flirted with support for Tibet’s secession from China. As one scholar put it, “The leveraging of Tibetan separatism occurs in the context of a global US stratagem, which uses secession as one approach to recalcitrant countries and what US strategic planners term peer competitors.”
Now, let us turn to Ukraine. At first glance, the model seems to fit neatly. Back in the Cold War, the United States was A and the Soviet Union was B. In the 1990s, the Soviet Union split apart into Russia (B) and Ukraine (C). In 2022, Russia and Ukraine went to war, the United States helped the weaker side, Ukraine, and Russia became trapped in a quagmire. Does this mean that US policy toward Ukraine is driven by brutal Realpolitik—fighting until the last Ukrainian?
Not really.
First of all, yes, the United States won the Cold War, but Washington did not directly engineer the collapse of the Soviet Union. Instead, Soviet reformers like Mikhail Gorbachev mainly responded to internal problems. In other words, rather than being murdered, the Soviet empire, as Vladislav Zubok put it, “committed suicide.” Furthermore, US officials were quite ambivalent about the breakup of the Soviet Union, fearing potential chaos and loose nukes.
Today, it is hard to imagine the Biden team sitting around, working out how best to lure B and C into war. After all, Washington warned Moscow against invading Ukraine. And of course, in the real world, many additional factors that are ignored in this model are involved, including morals and norms, as well as third-party actors like China and Europe.
But even if US policymakers are not truly Machiavellian, it is still important that a Realpolitik logic underpins American aid to Ukraine. At some level, US policymakers must appreciate the appeal of a great-power adversary breaking apart and then fighting itself. No American leader may ever admit it, and they might be shocked at the very notion, but this ruthless logic lurks in the background. And so, at the very least, Realpolitik thinking smooths the path to helping Kyiv. After all, if US aid to Ukraine worked against Realpolitik logic, there might be greater opposition.
American aid to Ukraine promotes a noble cause, is in US interests, and serves a tough-minded Realpolitik logic—all at the same time.