Teams enter an Olympic opening ceremony in a prescribed order that looks arbitrary. Every element of it was adopted to resolve a specific problem about precedence.
Precedence is a genuine diplomatic problem
Any procession of nations requires an order, and any order implies ranking unless it is governed by a rule everyone accepts as neutral.
Alphabetical order in the host country's language is the standard solution, because it is arbitrary in a way that cannot be read as a judgment.
It also changes from Games to Games, which prevents any nation from acquiring a permanent position and the status that would come with it.
Greece leads for reasons of origin
The delegation representing the birthplace of the ancient Games enters first, a convention that acknowledges lineage without conferring competitive standing.
That single exception establishes the ceremony as a historical claim rather than a purely administrative parade.
It is a low-cost tradition, since it costs no other nation anything and settles the most obvious question about who should go first.
The host enters last for practical reasons
Closing the parade with the home team produces the loudest reception at the end, which is exactly where a ceremony director wants it.
It also gives the host a moment of ownership after having spent the entire procession welcoming everyone else.
Future hosts have been added ahead of the current one in recent practice, which turns the end of the parade into a handover as well as a climax.
Flag bearers carry a separate set of customs
Selecting who carries the flag is a decision each delegation makes for its own reasons, and it has become a way of signaling values rather than ranking athletes.
Pairs of bearers, one from each of two categories, were introduced to make that signal explicit and consistent across delegations.
The practice of dipping or not dipping the flag while passing officials has its own long history, and the American convention of keeping it raised is among the most discussed.
The ceremony keeps absorbing new elements
Combined delegations, athletes competing without a national team and joint marches have all required adjustments to an order designed for a simpler arrangement.
Each addition is negotiated, and each becomes precedent that constrains the next edition's organizers.
The parade is therefore a record of accumulated diplomacy, which is why it takes so long and why nobody can shorten it.

