A provocative set of essays set back by some clear historical blind spots on the author's part. Mostly noteworthy by a general failure to consider the nationalism that is inbuilt into imperialism which I would argue is the worst form of nationalism.
Hobsbawm also argued in his essay on the Falklands War, which is probably the closet he gets to critically examining English nationalism - he does look at Scottish and Welsh nationalism earlier in the work but generally forgoes any sort of criticism of English identity, that the left should adopt nationalism which I think is impossible because nationalism implies the innate belief that you are superior to "the other" and we are seeing it's dangerous, illogical group think outlet with the enforced mourning going on for the Queen, something that implicitly tells victims of the British Empire that they are not wanted in conversations surrounding the future of the country and also English descanters that they are not wanted because they have dangerous ideas.
I think nationalism is justified only as a sort of provisional measure if it comes to self-determination. If a people are exploited by another, larger people whether it be for wealth, land, resources, or due to some racial or cultural bias that people have a right to self-determination, but this only gets you so far in the end. Hobsbawm is right to say that Scotland and Wales would struggle to make it alone outside of the UK - these questions are far more relevant now due to the aftermath of Brexit, but of course my country the Republic Of Ireland proved there is an alternative option, joining a larger, more democratic power structure like the EU, but leftwing nationalists hate the EU, although granted I don't know what the authors view on the institution was.
The Russo-Ukraine War is obviously a very good current, real-time case study for the justifications and cautions about self-determination.
So, how would I approach this conflict using nationalism as a framework?
Firstly, Putin apologists like to point out the two separatist Republics in the Donbas, who are both pro-Russian the argument being that Ukraine is denying them self-determination. In and of itself this is not an entirely unreasonable argument and if this region simply wanted to be part of Russia the matter might be closed there.
But anyone who has been paying attention since the war started back in February knows that Putin does not believe that Ukraine should exist as a body-politic, it's clear he only recognized the automony of the two breakaway republics not out of protection for them, but as a pretext for his planned invasion of Ukraine, after all he blamed Lenin for inventing the Ukraine.
The majority of Ukrainian's however don't want to be part of Russia and so it is reasonable to then attest that they have a right to self-determination, something they overwhelmingly voted for back in 1991. Then of course we have the question of fascism, which is another one of the toxic, logical end points of nationalism, tankies will say Zelensky is working with fascists, while in fact the Azov Battalion is only a small proportion of the Ukraine army and of course they fall silent when you mention the Neo-Nazis Putin has on his payroll (The Wagner Group anyone?)
This is all to say that I think countries have a right to self-determination but taken as it's own ideology there's nothing to be happy about when it comes to nationalism, ideally all peoples would live in a borderless world, and learn to value otherness, it would save so much bloodshed, but like Hobsbawm I don't really know how we end up getting there unless it's through large super structures like the European or African Union's. Although these entities being left by themselves, would only amount to a sort of nationalism as they reival each other for increasingly scant global resources (climate change).
Basically, people are a mess.