There's really no continuity between the Hasmonean kingdom of Israel and the modern State of Israel except in the imagination of Israeli ultranationalists.
Nah, pretty much in the imagination of most Zionists. And all religious Jews at all, from Brooklyn to Iran.
In terms of bourgeoning national movements, you can grant nothing a better credit than to the imagination of the public.
It's nice and good. After all, we don't play here for absolute justice in front of a judge in the skies - We just go for what the people want and dream of. And that is - a Jewish nationhood in Zion.
Anyway, I'm not sure any Venetian and a Sicilian of the 18th centruy could see much sense in a future idea of a pan-Italian nation that includes them both. Jews could, at any given time.
For this same reason I don't go all out against the use of the term Palestinians in some cases. Every group of people has the right to call themselves whatever they like, and to want whatever they wish.
But beside this, you may still want to determind which are nations or peoples in historical terms.
So let's do it:
Throughout the centuries, Jews lacked demographic concentration and possibly genetic lineages - which are both relevant factors.
But they shared a national spirit (in the sense of a glorified past and a hope for a rebuilding of Zion in the future), religion and traditional customs, to some extent a language (which is now fully revived) or several exclusive diaspora languages, and also their designation or exonym.
Several decent factors, I'd say, for around 1900 years of diaspora - to help Jews go ahead of many other continuously existing nations if we want to compare.