I’ve just finished the final two books in the series to date.
Black Widow is the 16th book. I’m sorry to have to wait for #17 later this year.
In general the books have gotten better and better. Black Widow revolves around ISIS terrorist attacks on western targets.
On the other hand the blatant Pro-Israel bias has become more annoying.
The Allon story has gone on so long that Silva plagiarizes from himself. (Is that a thing?)
He cuts and pastes phrases, sentences and possibly paragraphs from earlier books.
I’ve read all 16 books since Oct 2016.