The Egyptian military's decision to arrest Muslim Brotherhood leaders is a huge step backward. It more or less ensures that the movement will draw the wrong lesson from this latest Islamist experiment with electoral democracy.

From the point of view of Arab Islamists, engaging in elections hasn't been a great success. That's especially true now that their most important win -- in parliamentary and presidential votes for the region's oldest Islamist movement, the Brotherhood, in the Arab world's most populous nation, Egypt -- has been crushed by a coup d'etat.

Algeria's Islamic Salvation Front won the first round of parliamentary elections in 1991, only to be blocked from power by the military -- a bloody civil war followed. Hamas won elections in Gaza in 2006, but was ostracized by the U.S. and some other countries, because of the uncompromising position it took against Israel's right to exist.

You could add Syria and Libya to this list of Islamist failures. Arguably, had Syria's initial peaceful uprising in 2011 led to a largely bloodless overthrow of President Bashar al-Assad, Syria's Muslim Brotherhood would have been a leading candidate to benefit in ensuing elections. Assad, however, refused to follow the script, unleashing civil war.

In Libya, Islamists ran for election after the removal of Muammar Qaddafi, and lost. Their militias have since been elbowing their way to power anyhow, to the country's heavy cost.

Yet there has been one qualified success for Islamists who pursue power through the polls. In Tunisia, the Ennahda party won elections in 2011, after the first revolution of the Arab Spring. True, Ennahda is in a difficult power-sharing arrangement with other non-Islamist parties, and is under pressure from more-radical Salafists. Ennahda's own prime minister at one point proposed dissolving the government in favor of a technocratic one, resigning when the party disagreed. Nevertheless, Ennahda remains engaged in the messy horse trading that most democracies involve.

Ennahda was as smart as Egypt's Muslim Brotherhood said it was when it started talking about organizing for elections after the fall of President Hosni Mubarak in 2011. At the time, the Brotherhood said it didn't want to win a majority in parliamentary elections, that it didn't want to rule alone and wouldn't put up a candidate for the presidency. It reneged on all these ideas.

Ennahda, by contrast, backed a non-Islamist for president after winning the election. The party has made a lot of mistakes, too, and Tunisia is hardly the model for democratic development that it has the potential to be. Yet it does prove that Arab Islamist parties can advance their interests in a democratic system -- if they share power. This is the lesson that Egypt's Muslim Brotherhood should learn. It is one they seemed to understand intuitively in 2011, but promptly forgot as the prize beckoned, and sought to monopolize it instead.

The Muslim Brotherhood has proved extremely adaptable as an organization since its formation in the late 1920s. Still, I doubt they will draw the right lesson from former President Mohamed Mursi's abortive year of rule. The military's decision to issue arrest warrants for the group's leaders will feed the paranoia of a movement that has spent much of its history underground and has at best a shallow understanding of the democratic process. After all, many Islamists believe democracy to be heresy, leaving violence as the only path to pursue political power.

At a rally of Mursi's supporters in Cairo following the coup's announcement on the night of July 3, speakers whipped up the crowd by drawing the other -- and most obvious -- conclusion from the largely unsuccessful history of Islamist experiments with elections: Democracy is for everyone else, but it isn't allowed for us.

(Marc Champion is a member of the Bloomberg View editorial board. Follow him on Twitter.)