Published in 1907, Joseph Conrad’s novel “The Secret Agent” tells the story of a cell of foreign operatives who plot to blow up a London monument. The high-profile bombing was not intended to kill, but rather to damage the confidence the British people had in the institutions of their government and society.

Although the author does not specify who the terrorists work for, the fact that the cell leader is named Mr. Vladimir provides a powerful clue. Indeed, from the reign of the czars through the Soviet era to today, Russia has a long and troubling history of attacking its geopolitical rivals by interfering in their internal affairs in order to foment suspicion and strife.

In our time, the weapon of choice is not a bomb but social media. As Noel Gallagher described in her Aug. 2 Press Herald story, nearly 4,000 Russian-controlled troll accounts have swamped Twitter and other social media with more than 3 million deceptive messages targeting political leaders since the spring of 2015. As a centrist who strives to bring the Senate together on common ground, I am not surprised to have been the target of 273 of these attacks.

On the Senate Intelligence Committee, I have questioned government and private-sector experts on Russia’s concerted campaign to undermine the fabric of our elections. While these efforts did not change the outcome of the 2016 election, they were a nefarious attack against our country.

During that election, an estimated 150 million Americans were exposed to deceptive social media content created by the Russia-based Internet Research Agency. Moreover, 29 million people received news feed content from the Kremlin-directed IRA’s 80,000 posts on Facebook pages it created. According to the Intelligence Community, Moscow’s campaign blended covert operations – such as hacking – with other efforts by Russian government agencies, state-funded media, third-party intermediaries and paid social media trolls.

At a recent Intelligence Committee hearing, Dr. John Kelly of the social-media analysis company Graphika, confirmed my belief that Russia’s ultimate goal is to undermine our faith in democracy and the bonds that unite us as Americans. Part of this effort, he said, includes attempts to sway particular events or elections with disinformation.

The Russians are trying to exacerbate growing political and social divisions in our country. It is telling that Russia’s efforts are not aimed at one candidate or one political party – Republicans and Democrats alike are being attacked. In fact, the Russian attacks go beyond one country. In addition to the United States, we’ve seen Russian influence efforts in western elections in nations such as France, Germany and Great Britain.

This is not just about the 2016 election. There is every indication that Russian social media attacks actually increased in 2017 and that its efforts will continue through the 2018 election and beyond.

In addition to educating the public and the news media on how to better guard against this manipulation, it is essential that government take decisive action to protect our elections.

To that end, I have cosponsored the bipartisan Defending Elections from Threats by Establishing Redlines (DETER) Act, which sends a powerful message to any foreign nation that attacks on American candidates, campaigns or voting infrastructure will produce severe consequences.

This legislation will swiftly impose harsh sanctions on Russia if it attempts to undermine our electoral process again. It would also direct the administration to develop a plan to prevent interference by any foreign country.

Our elections are administered by the states, so it is crucial that our defenses are strengthened at that level. The FY18 Omnibus provided $380 million for election security, and Maine has been awarded $3.3 million of this funding to help secure election systems.

The Secure Elections Act I co-sponsored would bolster state cybersecurity defenses and provide security clearances to state officials so they can address threats found in classified channels. Notably, no chief state election official had a clearance nearly eight months after the 2016 election.

The Department of Homeland Security has sponsored up to three officials per state for clearances, but as of this March only 20 out of the 150 had full clearances. One expert I questioned said that Russian actors have scanned election systems in all 50 states for vulnerabilities.

Ours is a government of the people, by the people and for the people. Protecting its integrity requires all of us – citizens, the news media and government leaders – working together. The attack by Mr. Vladimir and his conspirators was fiction, but the threat it described is all too real.