I’m pretty sure that John Boehner doesn’t want a government shutdown. I doubt if Barack Obama wants one. In fact, I suspect that only a minority of the GOP, and practically no Democrats, want to see a shutdown or believe that the threat of it will lead to meaningful policy gains.

That’s why I think there may be no shutdown. And yet . . . well, here are the five biggest reasons that we could get a shutdown debacle, or a damaging debt-limit breach, anyway.

5. This one is specific to the debt limit: Last time around, a small chunk of Republicans chose not to believe in the damaging effects of a breach. As disbeliefs go, this one is somewhere between not believing in gravity and not believing in evolution . . . and like the latter, I suspect a lot of it is lip-service “belief” rather than true, act-on-it type belief. Still, some of that could exist, and could push Republicans and the nation into catastrophe.

4. This one is a potential leadership problem, on both sides: We’ll be in trouble if either Barack Obama or John Boehner adopts the idea that a shutdown will “teach them a lesson” or “break the fever.” It won’t work . . . but if they buy the idea that it will, then this kind of thinking could damage the nation in the meantime.

3. Here’s the thing: We’re a couple of weeks from the government needing funding. Everything so far has been about getting Republicans to the point where they can actually start negotiating next year’s budget, as opposed to just holding their breath until they turn blue in the hopes that it will get everyone to give them everything they want. But at some point, we’ll be past that, and then the real negotiations can begin . . . and at that point, I worry that the GOP’s lack of policy expertise will come into play and make negotiations more difficult, and more time-consuming, than they need to be.

2. Barack Obama isn’t especially popular right now (HuffPollster’s average has his approval rating at 43 percent) and his reputation for fighting is probably off some after Syria and Summers. But within the closed-information feedback loop, Obama is hated and scorned by most Americans and is ready to surrender on anything at any time (well, at least when he’s not being a devious Chicago politician). As Steve Benen says, that could easily lead to an unnecessary debacle — the problem not being that Republican negotiating strategy is irrational, but just that it’s rationally proceeding from a bunch of fiction.

1. The most likely reason we get a shutdown or a debt limit breach? That’s easy: Even though most Republicans probably know it’s futile to expect Democrats to capitulate on Obamacare, and even though most Republicans probably know that it will hurt the party . . . on an individual level, too many Republican members of Congress may turn out to be so terrified of allowing any distance between themselves and the Ted Cruz-types that they’ll choose likely disaster instead.

Add it all up, and . . . I have no idea how to set odds for this one. But those are the five more likely ways we get into trouble this fall.