As I noted in my last post, it’s a little hard to figure out ISIS’s strategy following its second videotaped execution of an American citizen in less than a month. Over the last two years, the group has shown impressive strategic acumen, growing into the world’s wealthiest terrorist group and something close to a viable theocratic state. It has achieved those aims via a strategy of gaining and consolidating control within Iraq and Syria—two of the world’s most unstable states—while, unlike al-Qaida, avoiding action that would provoke a major U.S. response.

Why is it now carrying out very public killings that seem designed to provoke an escalation of U.S. military involvement in Iraq, and maybe even in Syria? The fate of al-Qaida over the last 13 years doesn’t seem like a wise model to follow. But here are a few possible explanations for what ISIS higher-ups are thinking.

1. They feel cornered.

ISIS accomplished quite a bit in 2013 and the first half of 2014, including taking over nearly a third of Syria and the city of Fallujah in Iraq. Most remarkably, it managed to do this in such a way that both the Syrian and U.S. governments largely left it alone.

It’s interesting to ponder what might have happened if ISIS had stopped conquering territory after Fallujah and simply focused on consolidating its rule over the areas it already controlled and enforcing Shariah law. If that were the case, it’s possible that there might be a de facto, relatively stable Islamist state between Iraq and Syria right now.

But a group that proclaims itself a caliphate can’t really stop expanding, and it couldn’t stay under the radar forever. The fall of Mosul was one tipping point, leading the United States and Iran to up their assistance to the Iraqi government and muscle out the problematic Nouri al-Maliki. Last month’s encroachment into Kurdistan and the potential massacre of Yazidis on Mount Sinjar were another tipping point, pushing the reluctant Obama administration to finally launch airstrikes.

At that point, with the bombs already dropping, ISIS may have calculated that there was nothing more to be gained from avoiding a confrontation with the United States, and struck back with one of the most politically powerful weapons in its arsenal.

2. They don’t think the U.S. will act.

ISIS can read polls too. They know how reluctant Americans have been to see the country involved in another Middle East entanglement. This administration has been extremely hesitant to increase American involvement in Iraq and even more reluctant to get involved in Syria. A president who tells the press that “we don’t have a strategy yet” for ISIS certainly doesn’t sound like one who’s in a rush to go to war.

ISIS may believe that it can continue to demonstrate that it can strike the U.S. by executing these prisoners, and that the U.S. isn’t going to do anything about it. If this really is their thinking, ISIS honchos don’t have a very good grasp of history. Americans are traditionally reluctant to go to war right up until they do. Saddam Hussein didn’t think the U.S. would really attack him either.

3. They think this is working.

Terrorist groups thrive on attention, and the Foley killing has done more to make the group a household name than any of its other actions. Beyond media attention, we don’t know what impact the killing had on international recruitment. ISIS is an extremely media-savvy organization that has sustained itself on its ability to recruit fighters from abroad, including from Europe and the United States. If the group’s leaders believe these killings further that goal, they may keep at it, despite the possible consequences on other fronts.

4. They’re upping the price.

We all know that the U.S. government has a policy of not negotiating with terrorists (except when it does). ISIS apparently asked for $132 million for Foley, which, to put it bluntly, does not sound like the demand of a group that plans to release its hostage. That amount is more than al-Qaida affiliates earned in total from ransoming dozens of European hostages over the past five years.

By contrast, ISIS is reportedly asking for $6.6 million for a 26-year-old American woman in custody, which sounds like a figure you might quote if you’re actually looking to make a deal.

Is there any chance of this? The Obama administration would lose all credibility if it paid a ransom at this point. But Jabhat al-Nusra’s recent release of American writer Peter Theo Curtis may have demonstrated an alternative plan. U.S. Ambassador to the United Nations Samantha Power apparently introduced Curtis’ family to emissaries from Qatar, who negotiated with the al-Qaida-linked group for his release. (We still don’t know the terms of that deal.) ISIS, which has released European hostages in the past, may be wondering if third-party intermediaries might make a similar deal for the Americans it still has in custody.

It also seems significant that ISIS is apparently now threatening a British citizen in its custody. The British government also doesn’t pay ransoms to terrorist groups, but perhaps ISIS is testing how steadfast the Brits are in adhering to that policy.

5. This was the plan all along.

It may not seem very logical from the outside for ISIS to provoke the United States into open warfare. But while ISIS’s tactics have differed form al-Qaida’s thus far, it shares its former patron’s antipathy to America’s presence in the Middle East and now may feel it’s acquired enough territory, money, weapons, and manpower to pursue a time-honored strategy of provoking the U.S. into military overreach. This seems like hubris, but that too is not exactly unprecedented.