At its most apologetic the position seems to be that empire is not necessarily a bad thing.

En su versión más apologética, la posición parece (que debe) ser que ese imperio no es necesariamente algo malo.

http://dle.rae.es/?id=3EcrVBn

Diría yo... :-)

O bien:

La posición más apologética parecería ser que ese imperio no es necesariamente algo malo.

Saludos cordiales y felices festividades navideñas.

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Note added at 31 mins (2017-12-27 20:46:15 GMT)
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O también:

En su rol más defensivo, la postura sostendría que ese imperio no debería ser algo necesariamente pernicioso-malo-negativo...

At its most apologetic parece querer trasladar la idea de que esta es la última excusa o justificación; a modo de última disculpa, o más literalmente, en su máximo grado de disculpa. Esto es, no parece decir que la máxima, mayor o mejor justificación o defensa sea (...), sino que, como mínimo / como poco, la idea de que el imperio no es necesariamente una mala cosa es el argumento generalmente aceptado sobre la cuestión ("en ciertos círculos de Inglaterra y en los Estados Unidos").

El contexto más amplio parece corroborar esta idea;
(...) there is still nostalgia for a benign image of the British Empire in certain circles in England and in the United States (as if self-sacrifice, afternoon tea, cricket, rugby, and political or￾der were all that the British Empire had to it). British bestseller lists in 2003 had any number of books devoted to telling stories about those who had sacrificed themselves for empire. At its most apologetic, the position seems to be that empire is not necessarily a bad thing. More stridently, it marks the revival of the old Roman idea of homo sacer: we Brits, Americans, etc., are capable of self-rule, and others are not; they need our savoir faire and we will impose it on them.

Como mínimo, la idea prevalente parece ser la de que el imperio no es necesariamente algo malo.

It means that at the person's* most apologetic of moments (i.e., his most compassionate and understanding of moments), the absolute most (think: worst that he or she could say about empire [as a construct and not one empire or 'that' empire]) is that it's not necessarily a bad thing, i.e., leaving open the possibility that empire(s) can also lead to good things.

* = who wrote/created the policy

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Note added at 1 day 14 hrs (2017-12-29 10:59:09 GMT)
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A Saltasebes:

Entiendo que aún así, sintiendo lo más pena posible, lo más (en contra del imperio) que transmite la política es que no es necesariamente algo malo, dejando a entender que bien puede ser que el imperio sea algo bueno. That even at the author's most apologetic, i.e., where he or she conveys the greatest remorse or sorrow, the absolute worst that the policy has to say is that empire is not necessarily bad. At its least apologetic, the policy's underlying message would be even more favorable, of course.

This is how I understand the text as a native speaker of English. That said, I could be wrong. Let's see what others think.