Edit: meant to respond to u/Kienan

No matter how you feel about the stunning and brave national socialists

I can both criticize the evils of the Nazi regime and claim that the unilateral -- and not uncontroversial at the time -- UK/France defense pacts with Poland were the primary cause of the broader Second World War. The modern equivalent of Halifax's agreement with Poland would have been Victoria Nuland creating an agreement with Ukraine that obligated the US to put troops on the ground in the event of a Russian invasion, without the approval of congress.

it's another to legitimize the violent expansion of a rival

The history of the Free City of Danzing and the German population of Poland should be understood here. In Danzing, Germans were being deprived of rights and property under the Polish government, a situation that accelerated after Halifax's agreement with Poland. Why not ethnically cleans Germans if Britain will come to your aid if Germany tries to prevent it?

No matter how you feel about the stunning and brave national socialists

I can both criticize the evils of the Nazi regime and claim that the unilateral -- and not uncontroversial at the time -- UK/France defense pacts with Poland were the primary cause of the broader Second World War. The modern equivalent of Halifax's agreement with Poland would have been Victoria Nuland creating an agreement with Ukraine that obligated the US to put troops on the ground in the event of a Russian invasion, without the approval of congress.

it's another to legitimize the violent expansion of a rival

The history of the Free City of Danzing and the German population of Poland should be understood here. In Danzing, Germans were being deprived of rights and property under the Polish government, a situation that accelerated after Halifax's agreement with Poland. Why not ethnically cleans Germans if Britain will come to your aid if Germany tries to prevent it?