What's the incorporation of Texas got to do with a moderate UNGA resolution that does not prejudge the sovereignty issue or set an unrealistic deadline for negotiations?

The Secretary(Shultz) reiterated that the US supports the principle the UK fought for in the Falklands War, to which Pym (UK Foreign Secretary)said he wondered how far back one must go to unroll history—to the incorporation of Texas into the U.S.? (source: Foreign Relations of the United States, 1981–1988, Volume XIII, Conflict in the South Atlantic, 1981–1984, Document 398)

Why did Pym note the clause in bold? What’s the incorporation of Texas got to do with a moderate UNGA resolution that does not prejudge the sovereignty issue or set an unrealistic deadline for negotiations?

Thank you very much.

Some context missing here?

I infer that Schultz was arguing for some position that Pym considered ‘unrolling history’*, and therefore looked to an example of the same that the US would consider as preposterous as Pym (I assume) considered Schultz’s proposal.

The fact that a General Assembly motion would not be binding doesn’t (didn’t ) mean that it had no significance for framing future debate on the issue, and more broadly setting the tone and context for relations between the UK and other countries (not least the US).

*I’m guessing that it might have been a proposal that the Falklanders should have a referendum on some compromise allowing Argentina some special status there?

Thank you for your response.

The background of my post is as follows:
During his Sept. 28 bilateral breakfast with the Secretary (Shultz)on the margins of the UNGA, Pym (British Foreign Secretary)rehearsed British objections to an UNGA resolution on the Falklands in familiar but forcefully animated terms. Pym asked for help in encouraging the Argentines to agree to a formal end to hostilities and said the UK could see no point in discussing a resolution for the immediate future. Now is not the time to talk with the Argentines about the long term, he argued. The Secretary told Pym that it is difficult for the U.S. to oppose a moderate resolution that does not prejudge the sovereignty issue or set an unrealistic deadline for negotiations.

This is presumably in the aftermath of the actual fighting in the Falklands. The UK government position - and a major and strident part of public opinion - would have been that the Argentine military regime, by resorting to force, had forfeited the option for any sort of compromise, even with a democratic Argentine government, and that any sort of resolution not recognising that fact would implicitly prejudge the sovereignty issue and re-open the possibility of “unrolling history”. The US wouldn’t re-open the status of Texas decided in the 1840s, so why would the UK do so in relation to the Falklands (decided at around the same time)?

Thank you for your illustrative explanation, PatrickLondon.
I think he then British Foreign Secretary showed his wit to nicely refuse the UNGA resolution supported by the US although the US was trying hard to push Britain to accept the resolution to get on the good side of Argentina, aiming to make up the damaged relationship by siding with the UK before the outbreak of Falklands War. The US must have felt upset and rueful. Nobody knows whether or not Britain could win the war without US assistance.

Mod hat on: UNGA? Please don’t drop unfamilar acronyms in a post without explanation. And I shouldn’t have to click on a link to discover if it is interesting enough to me to click on.

Thank you for your reminding and I’m sorry for any inconvenience. UNGA is the short form of the United Nations General Assembly.