The wide wake that the Islamic State of Iraq and Syria (ISIS) is leaving across the Levant is mysterious in a number of ways. How they have so easily overwhelmed a third of Syria and a quarter of Iraq is one. But perhaps most mysterious is the American response to the rise of the Islamic State. Though the ascendancy in the region of the very force the war on terror is supposed to eliminate from the region would seemingly be blipping away on the American radar, America was silent as ISIS advanced. And the only thing more mysterious than the American silence was the sudden explosion of that silence by the recent airstrikes on Iraq. Why was America so strangely silent as ISIS established the Islamic State, and why has America so suddenly changed its policy?

America does whatever it wants. So, if they did not oppose ISIS, it’s because they did not want to oppose ISIS. And, if they did not want to oppose ISIS, it’s because, somehow, the ISIS advance was consistent with American interests in the region.

What those interests might be can best be answered by looking at where that advance was. ISIS has poured through Syria, Iraq and is now trickling into Lebanon. Iraq, Syria and Lebanon are precisely Iran’s three great allies in the region. The pattern is not a coincidence. ISIS’s interests coincide perfectly with America’s. America has long been bent on removing Assad from Syria in order to isolate Iran. But Syria is no longer Iran’s greatest ally in the region: Nouri al-Maliki’s Iraq is. And America has for some time now been seeking a change of his regime as well. And Lebanon is home of Iran’s ally Hezbollah. Notice that if the pattern breaks and ISIS attacks Jordan, then Israel, and perhaps the States, would come to Jordan’s aid. Perhaps America has not stopped ISIS from doing its work because ISIS is simultaneously doing America’s work: regime change and weakening of Iran’s allies.

Though seemingly counterproductive to side with your worst enemy, by siding with the very side you are fighting in Syria, the States has a long history of siding with their worst enemy to remove the enemy of the day. Siding with ISIS is merely an awkward variation on a well established historical theme.

One of the theses of William Blum’s book on American interventions, Killing Hope, is that in the closing years of World War II and in the years immediately following the war, America consistently allied with Nazi and Nazi sympathizers to prevent and eliminate communist governments while America simultaneously fought the Nazis. This use of the worst enemy to fight the current threat occurred, at least, in China, Italy, Greece, The Philippines, Korea, Albania and Germany itself.

The pattern continued with the financing and arming of the Mujahadeen in Afghanistan. And it continues today with the support of the Islamic extremists in Syria and the neo-Nazi and Nazi sympathizers in Ukraine.

So it is not at all inconsistent with history that the United States should, by not opposing ISIS, support ISIS in doing the work the States had not been previously able to do. ISIS success would mean the weakening or changing of regimes in the countries necessary to isolate and weaken Iran. Though seemingly undesirable to allow ISIS to rule the region in the incarnation of the Islamic State, one need look no further than ISIS’s backers in Saudi Arabia for proof of America’s willingness to continue working with a Salafist state. And the more brutal the allied or client state, the better for America. History has continuously shown that America likes to support brutal dictators, as opposed to democratic regimes, not only because democratic regimes work in the interest of their voters and dictators are willing to work in the interest of America in exchange for American support, but because, when American interests no longer include the brutal dictator, it is easy to justify removing the dictator on the very grounds that he is brutal.

So, the answer to the first question may be that America was silent as ISIS advanced because American interests coincided precisely with ISIS’s advance. The countries that ISIS was conquering were precisely the countries that America wanted to weaken or to carry out regime changes in in order to isolate and weaken Iran.

So, if the answer to the first question is that America allowed ISIS to succeed because America benefited from ISIS’s success, then why has America suddenly broken its silence and unleashed its aerial assault on ISIS in Iraq?

Though America benefits from ISIS’s success in Syria, Iraq and Lebanon, America would benefit even more by removing Assad and al-Malaki without being left with ISIS in those lands. So, ISIS does double-duty and creates a situation in which American foreign policy interests cannot lose. Because, before ISIS fully accomplishes its goal, the weight of its threat on Iraq gives the States enormous leverage to accomplish regime change on its own.

An historical event does not exist in isolation: it must be seen as a link in a chain of events. If it is hard to understand that link, then look to the links immediately before and after it. Why did America suddenly start to fight ISIS in Iraq? It may be partly to protect its Kurdish allies; it may be partly to protect its military personnel and diplomats in Irbil and Baghdad, but there may be a deeper political, foreign policy motivation as well.

To understand that motivation, look to the events linked immediately before and immediately after America’s entry into the Iraq. When President Obama announced that he had authorized the strikes he explained that Iraq was "going to have to show us that [they] are willing and ready to try and maintain a unified Iraqi government that is based on compromise. . . . We’re not going to let them create some caliphate through Syria and Iraq. But we can only do that if we know that we have got partners on the ground who are capable of filling the void." In other words, America does not have that partner on the ground currently. Obama is using the threat of ISIS as leverage for regime change in Iraq. America will only save Iraq if Iraq installs a government that is capable of the kind of unity and compromise that the al-Malaki government has been unable to provide.

So either ISIS will accomplish the desired change in Iraq or the States will by only offering to save Iraq from ISIS if there is regime change in Iraq.

The link after the bombing confirms the point of the one before. Only days after the commencement of U.S. involvement in Iraq, Iraqi President Fuad Masum, in what al-Malaki has called a coup, refused to appoint al-Malaki as Prime Minister. The US has loudly supported Masum’s ouster of al-Malaki. Deputy Assistant Secretary of State for Near Eastern Affairs Brett McGurk said that that the US" Fully support[s] President of Iraq Fuad Masum as guarantor of the constitution and a PM nominee who can build a national consensus." State Department Deputy Spokeswoman Marie Harf added that the Iraqi prime minister needs to "represent the aspirations of the Iraqi people by building a national consensus and governing in an inclusive manner."

So the United States broke their silence over ISIS in Iraq for the same reason they maintained their silence over ISIS in Iraq: regime change in Iraq. Obama made it clear that America would only send help to Iraq if Iraq removed al-Maliki from power. Obama then sent help, and Iraq immediately began the removal of al-Maliki from power.

So the silence and the breaking of the silence are not inconsistent. They were two compatible responses designed to achieve regime change in Iraq.

To see why America was silent as ISIS accomplished the very thing the war on terror was being fought to end and to see why America suddenly broke that silence with bombs over Iraq, the coincidences need to be seen as patterns. It is not a coincidence that America stayed silent while ISIS overran Iran’s allies in the Levant: America remained silent because it was Iran’s allies that ISIS was overrunning in the Levant. The three attacked nations form a pattern. It is also not a coincidence that Obama clearly implied that America would only bomb ISIS in Iraq if al-Malaki was removed from power, America then began bombing ISIS in Iraq, and President Masum immediately refused to appoint al-Malaki as Prime Minister in a move called a coup by al-Malaki.

Ted Snider has a graduate degree in philosophy and writes on analyzing patterns in US foreign policy and history.