In utilitarianism, “remoter effects” are the result of our actions influencing other people (and are hotly debated). I think that remoter effects are often overstated, especially (as Sir Williams said in Utilitarianism for and against) when they give the conventionally ethical answer. For example, a utilitarian might claim that the correct answer to the hostage dilemma  is to kill no one, because killing weakens the sanctity of human life and may lead to more deaths in the future.
When debating remoter effects, I think it’s worthwhile to split them into two categories: positive and negative. Positive remoter effects are when your actions cause others to refrain from some negative action they might otherwise take. Negative remoter effects are when your actions make it more likely that others will engage in a negative action .
Of late, I’ve been especially interested in ways that positive and negative remoter effects matter in political disagreements. To what extent will acting in an “honourable”  or pro-social way convince one’s opponents to do the same? Conversely, does fighting dirty bring out the same tendency in your opponents?
Some of my favourite bloggers are doubtful of the first proposition:
In “Deontologist Envy”, Ozy writes that we shouldn’t necessarily be nice to our enemies in the hopes that they’ll be nice to us:
In general people rarely have their behavior influenced by their political enemies. Trans people take pains to use the correct pronouns; people who are overly concerned about trans women in bathrooms still misgender them. Anti-racists avoid the use of slurs; a distressing number of people who believe in human biodiversity appear to be incapable of constructing a sentence without one. Social justice people are conscientious about trigger warnings; we are subjected to many tedious articles about how mentally ill people should be in therapy instead of burdening the rest of the world with our existence.
In “The Blues of Self-Regulation”, David Schraub talks about how this specifically applies to Republicans and Democrats:
The problem being that, even when Democrats didn’t change a rule protecting the minority party, Republicans haven’t even blinked before casting them aside the minute they interfered with their partisan agenda.
Both of these points are basically correct. Everything that Ozy says about asshats on the internet is true and David wrote his post in response to Republicans removing the filibuster for Supreme Court nominees.
But I still think that positive remoter effects are important in this context. When they happen (and I will concede that this is rare), it is because you are consistently working against the same political opponents and at least some of those opponents are honourable people. My favourite example here (although it is from war, not politics) is the Christmas Day Truce. This truce was so successful and widespread that high command undertook to move men more often to prevent a recurrence.
In politics, I view positive remoter effects as key to Senator John McCain repeatedly torpedoing the GOP healthcare plans. While Senators Murkowski and Collins framed their disagreements with the law around their constituents, McCain specifically mentioned the secretive, hurried and partisan approach to drafting the legislation. This stood in sharp contrast to Obamacare, which had numerous community consultations, went through committee and took special (and perhaps ridiculous) care to get sixty senators on board.
Imagine that Obamacare had been passed after secret drafting and no consultations. Imagine if Democrats had dismantled even more rules in the senate. They may have gotten a few more of their priorities passed or had a stronger version of Obamacare, but right now, they’d be seeing all that rolled back. Instead of evidence of positive remoter effects, we’d be seeing a clear case of negative ones.
When dealing with political enemies, positive remoter effects require a real sacrifice. It’s not enough not to do things that you don’t want to do anyway (like all the examples Ozy listed) and certainly not enough to refrain from doing things to third parties. For positive remoter effects to matter at all – for your opponents (even the honourable ones) not to say “well, they did it first and I don’t want to lose” – you need to give up some tools that you could use to advance your interests. Tedious journalists don’t care about you scrupulously using trigger warnings, but may appreciate not receiving death threats on Twitter.
Had right-wingers refrained from doxxing feminist activists (or even applied any social consequences at all against those who did so), all principled people on the left would be refusing to engage in doxxing against them. As it stands, that isn’t the case and those few leftists who ask their fellow travelers to refrain are met with the entirely truthful response: “but they started it!”
This highlights what might be an additional requirement for positive remoter effects in the political sphere: you need a clearly delimited coalition from which you can eject misbehaving members. Political parties are set up admirably for this. They regularly kick out members who fail to act as decorously as their office demands. Social movements have a much harder time, with predictable consequences – it’s far too easy for the most reprehensible members of any group to quickly become the representatives, at least as far as tactics are concerned.
Still, with positive remoter effects, you are not aiming at a movement or party broadly. Instead you are seeking to find those honourable few in it and inspire them on a different path. When it works (as it did with McCain), it can work wonders. But it isn’t something to lay all your hopes on. Some days, your enemies wake up and don’t screw you over. Other days, you have to fight.
Negative remoter effects seem so obvious as to require almost no explanation. While it’s hard (but possible) to inspire your opponents to civility with good behaviour, it’s depressingly easy to bring them down to your level with bad behavior. Acting honourably guarantees little, but acting dishonourably basically guarantees a similar response. Insofar as honour is a useful characteristic, it is useful precisely because it stops this slide towards mutual annihilation.
 In the hostage dilemma, you are one of ten hostages, captured by rebels. The rebel leader offers you a gun with a single bullet. If you kill one of your fellow hostages, all of the survivors (including you) will be let free. If you refuse all of the hostages (including you) will be killed. You are guarded such that you cannot use the weapon against your captors. Your only option is to kill another hostage, or let all of the hostages be killed.
Here, I think remoter effects fail to salvage the conventional answer and the only proper utilitarian response is to kill one of the other hostages. ^
 Here I’m using “negative” in a roughly utilitarian sense: negative actions are those that tend to reduce the total utility of the world. When used towards good ends, negative actions consume some of the positive utility that the ends generate. When used towards ill ends, negative actions add even more disutility. This definition is robust against different preferred plans of actions (e.g. it works across liberals and conservatives, who might both agree that political violence tends to reduce utility, even if it doesn’t always reduce utility enough to rule it out in the face of certain ends), but isn’t necessarily robust across all terminal values (e.g. if you care only about reducing suffering and I care only for increasing happiness we may have different opinions on the tendency of reproduction towards good or ill).
Negative actions are roughly equivalent to “defecting”. “Roughly” because it is perhaps more accurate to say that the thing that makes defecting so pernicious is that it involves negative actions of a special class, those that generate extra disutility (possibly even beyond what simple addition would suggest) when both parties engage in them. ^
 I used “honourable” in several important places and should probably define it. When discussing actions, I think honourable actions are the opposite of “negative” actions as defined above: actions that tend towards the good, but can be net ill if used for bad ends. When describing “people” as honourable, I’m pointing to people who tend to reinforce norms around cooperation. This is more or less equivalent to being inherently reluctant to use negative actions to advance goals unless provoked.
My favourite example of honour is Salah ad-Din. He sent his own personal physician to tend to King Richard, who was his great enemy and used his own money to buy back a child kidnapped into slavery. Conveniently for me, Salah ad-Din shows both sides of what it means to be honourable. He personally executed Raynald III of Tripoli after Raynald ignored a truce, attacked Muslim caravans, and tortured many of the caravaners to death. To Guy of Lusignan, King of Jerusalem (who was captured in the same battle as Raynald and wrongly feared he was next to die), Salah ad-Din said: “[i]t is not the wont of kings, to kill kings; but that man had transgressed all bounds, and therefore did I treat him thus.” ^