Word for an unavoidable decision

Question

I'm looking for a word that describes a situation where not making (or refusing to make) a decision is equivalent to choosing one of the options. I considered "ultimatum", but it seems overly aggressive for my use case. I looked over the synonyms for "ultimatum", but they were all worse.

A compound word or short phrase could be acceptable.

An example situation that may be described by this word would be the decision between doing something (that you aren't currently doing) versus not doing that thing. In such a case, not making a decision is practically equivalent to choosing to not do that thing.

Answer 1

Inevitable

You could phrase it like:

The decision was inevitable, regardless of whether you made it or not.

Answer 2

In your example, you have chosen not to do X by default. For example if you delay and delay making hotel reservations until all reasonable rooms have been booked, you have chosen not to go on that trip by default.

Dictionary.com, default:

failure to act; inaction or neglect: They lost their best client by sheer default.

Answer 3

An ultimatum typically has to come from an agent (e.g. a person, business, or government), and can't arise naturally as a matter of logic (either I do or don't do a thing, regardless of whether anyone else is involved). Not entirely clear from your description whether pressure is being applied from an outside force to make the decision.

I'd be delighted to be proven wrong, but I don't think you're going to find a single word for this in English. You expressed it pretty succinctly in your question, with "unavoidable decision".

I don't agree with saying "inevitable decision", as that carries some implication that the specific chosen option was inevitable, rather than simply that making the decision was inevitable.

If you're not satisfied with "unavoidable", a good alternative would be "inescapable". If that sounds a bit too tense, a different (but very uncommonly used) option is "ineluctable", which is related the word "reluctance". As in, you're reluctant to make the decision, but it is ineluctable.

That said, "unavoidable decision", or perhaps "unavoidable choice", express the notion well.