The parties that have received the most votes in Egypt’s elections are the Muslim Brotherhood’s Freedom and Justice Party and the Salafist al-Nour Party. Both are Islamist parties. Yet Western observers — including Obama administration officials — claim that the Muslim Brotherhood is a “moderate Islamist” group while the Salafists are radical.

There are indeed important differences between the Muslim Brotherhood and the Salafists, but they are really issues of timing and tactics rather than of goals or principles. One way to think of them is as Coke traditional formula and Coke Light.

The Brotherhood seeks to transform Egypt into a radical state governed by Sharia. The Brotherhood, however, is more cautious — one might say, smarter — in its tactics.

This caution is rooted in the organization’s history. After the Egyptian military seized power in 1952, the Brotherhood, which had a history of terrorist activity, was its main rival. The military suppressed the Brotherhood, sending some of its leaders to concentration camps and others to the gallows. It would be 20 years before the regime allowed the Brotherhood to operate, and even then only illegally.

Knowing it could again be shut down at any moment, the Brotherhood became very careful. Its leadership declared a strategy of “da’wa” — that is, long-term propaganda and organization to build a base of support. Only in October 2010 did the new Brotherhood leader, Muhammad al-Badi, say that the time for revolution had arrived. Within weeks, it helped launch the revolution that brought down President Hosni Mubarak.

In contrast, Salafi groups only began to emerge in the 1970s. The assassination of President Anwar al-Sadat by Salafi terrorists in 1981 triggered repression against them. But this was far less severe than the repression the Brotherhood experienced in the 1950s and focused on those responsible for the killing. Many groups continued to operate.

These groups were all small, based on community and campus organizing, and each had its own leader. A lot of the members had left the Brotherhood, which they found too moderate in behavior. They did not want to wait for revolution; they wanted it immediately. During the 1990s, many took up armed struggle and killed hundreds of people in terror attacks, focusing especially on killing Christians, government officials and tourists.

But they were crushed by the government in the end. Many of their leaders, while in prison, concluded that they had made a strategic error and renounced violence. They were largely inactive in the dozen years leading up to the 2011 revolution.

While the Brotherhood furnished organized cadres and played a central role in the events of January and February of this year, the Salafists were still recovering, though many participated, especially in the most violent activities, like the attacks on Christians and on the Israeli embassy.

Again, it should be emphasized that the Brotherhood and the Salafists have the same goals. But the Brotherhood is far more patient. It has learned the lesson of the Turkish Islamists: If you go slowly and conceal your aims, victory is far more likely.

Brotherhood leaders understand the disadvantages of going for power quickly. It will be more likely to lead to a clash with the army; the economy will suffer due to a loss of investment and loans. Indeed, Egypt is headed for a serious economic crash and the Brotherhood does not want to be in charge at the moment that happens.

Far better, Brotherhood leaders think, to work with the army as much as possible, perhaps even to support a non-Islamist president. Meanwhile, the Brotherhood could play the key role in writing a constitution that would move Egypt toward Islamism. It could take control of the education, social welfare and religion ministries, which would help it increase and strengthen the size of its support base through both ideological indoctrination and patronage.

On foreign policy, the Brotherhood is having great success in lulling the United States and the West to sleep, thus getting money and help from the West while denying it to the army or moderate forces. The Brotherhood would use its power to empty the Egypt-Israel peace treaty of content without officially abrogating the agreement. It could give a lot of support to Hamas and the Jordanian and Syrian branches of the Brotherhood without getting directly involved in any conflicts. This is a sensible policy.

In contrast, the Salafists want revolution right now and trust in God to overcome all problems and barriers for themselves. Take an issue like tourism. The Brotherhood might permit the sale of alcohol to tourists and let women wear scanty bathing suits on beaches where few Egyptians would ever see them, in order to keep revenue coming in. To the Salafists, this is mere treason against proper piety.

This kind of tactical difference is by no means uncommon in revolutionary movements. Lenin wrote a pamphlet, “Left-Wing Communism, an Infantile Malady,” about it. In this attack on the Salafist equivalents in the Marxist movement, Lenin quoted Friedrich Engels, the co-founder of Marxism: “What childish innocence it is to present one’s own impatience as a theoretically convincing argument!”

Lenin’s words fit the struggle among Egypt’s Islamists perfectly. A revolution, he explained, is:

A war which is a hundred times more difficult, protracted and complex than the most stubborn of ordinary wars between states, and to renounce in advance any change of [tactics], or any utilization of a conflict of interests (even if temporary) among one’s enemies, or any conciliation or compromise with possible allies (even if they are temporary, unstable, vacillating or conditional allies) — is that not ridiculous in the extreme?

And that’s why the Brotherhood’s approach generally succeeds and that of the Salafists fails. Of course, by their extremism, the Salafists will push the Brotherhood into a tougher stance, and by their readiness to use violence, they will help crush Christians, moderates and women who want more rights. The two groups will compete, but they will also work together, at least tacitly, in fundamentally transforming Egypt.

Barry Rubin is director of the Global Research in International Affairs (GLORIA) Center and editor of the Middle East Review of International Affairs (MERIA) Journal at Gloria-Center.org. His latest book, Israel: An Introduction, will be published by Yale University Press in January.