This op-ed was first published in Defense News.

America’s withdrawal from Afghanistan put vulnerable democracies around the globe at severe risk. Allies and partners who stood beside us in our fight now question our nation’s commitment to those difficult tasks. Nations who routinely balance the challenges of building their democracies against the seeming ease of aligning with autocrats now question the strength and validity of American support in that endeavor. Worse, opportunistic adversaries are plotting and calculating the ways they can undermine American efforts and capitalize on perceived weakness in our commitment and resolve.

Just a couple short months after America’s exit from Afghanistan, we can already see the geostrategic effects in the aggression of Russian President Vladimir Putin against the vulnerable country of Ukraine.

The Russian army is now amassing forces along the extended border between Russia and Ukraine. As Russia has done in the past, it is expanding its information and cyberattacks against Ukraine, it is fomenting dissent within the minority ethnic Russian population in eastern Ukraine and it is positioning a formidable military force to intervene in any strife that may occur in Ukraine as a result of Russia instigation.

Further, Putin publicly announced during his April 2021 state of the nation address his intentions to see a reunified Russo-Ukrainian state. All the pieces are in place for a Russian military offensive into Ukraine. Many feel the attack is imminent.

Now is the time for the United States to reassert its leadership. Freedom-loving people around the globe are looking to America for assurances we will live up to our values and defend those sacred ideals of life, liberty and opportunity that we hold so dearly. If we fail to act, we may very well see the rapid decline of freedom and democracy in all corners. The international order we rely on will be upended and our national prosperity will be imperiled.

The response to Russia’s aggression needs to be swift and across all aspects of American strength. I propose a concerted effort of diplomatic, economic and military activities. The administration has a key role to play. Congress can provide legislative tools and support; and our allies must join in the effort.

In quick order, the administration must make clear to Putin and other Russian leaders the costs they will personally incur if aggression against Ukraine does not stop. This means imposition of crippling personal sanctions and the seizure of personal assets of Russian oligarchs. Putin must be made to understand his failure to abide by the norms of international relations and his disrespect for the sovereign rights of nations will cause him and his cronies to be expelled from the international system and denied the prosperities they could achieve.

Congress can act now to define the extent of those sanctions and build legislative triggers to automatically authorize and impose sanctions if Russian actions become too aggressive. The Senate Foreign Relations Committee is examining such legislation right now. Let’s bring it to the Senate floor for debate and discussion. Congress’ attention and input in this matter will send a powerful message of U.S. commitment.

The United States must further dismantle the economic pressure points Russia is using on Ukraine. This means preventing the completion and operation of the Nord Stream 2 pipeline. If this pipeline becomes operational, Putin will have a powerful means to isolate Ukraine from a strong and reliable revenue source while entangling the energy sectors of our European allies with Russian gas just as winter arrives.

The pipeline is the economic version of a poison pill that we must save our friends and allies from being forced to swallow. Measures to prevent the completion of the pipeline have been proposed for consideration in the Senate version of the National Defense Authorization Act. They should be carefully considered and passed. And the Biden administration should reinstitute the key measures they rescinded on Nord Stream 2. Pressure must be maintained so the pipeline is not completed.

Lastly, the United States must show commitment to Ukraine’s defense through the provision of additional defensive capabilities: anti-tank weapons, anti-aircraft weapons, enhanced cyber defenses, training and partnership. All of these capabilities will make Ukraine a more challenging problem for Putin and his imperialist designs.

These defensive capabilities should be augmented by multilateral training and exercise events with the U.S. and NATO partners. Even rotational deployments to Ukraine show a resolve that may cause Putin to think twice before continuing aggression.

Since the fall of the Berlin Wall, the United States has largely been kept safe because we’ve proactively kept our global neighborhood safe. But peace from great powers like Russia and China are not certainties. If the United States fails to demonstrate reliable partnership to partners in the crosshairs of terrorists or thugs like Vladimir Putin, we can expect more attacks on democracies and vulnerable nations. We could quickly see Putin expand his aggression to other neighboring states, and China attack Taiwan and roll back the sovereignty of other Asian nations. Latin America could see a rise in authoritarian leaders. Around the globe, we could see freedom and liberty under attack and the rise of oppressive authoritarianism.

The world needs American leadership. We must demonstrate we have the will and strength to defend our values; and, that we are the essential partner for ensuring rights and freedoms for all people, protecting and advancing democracies, and defending international norms that provide peace and prosperity for all.

Sen. Joni Ernst, R-Iowa, is a combat veteran and member of the Senate Armed Services Committee.