I agree with the first part of this sentence, and the mechanics of how a country can run a current account deficit for centuries is part of my lecture notes, where Portugal and Canada are the two examples that I use. But I don't understand the second one.
Below is a figure of the current account divided by GDP since 1953, split in 1995, when there was a change in the source of the data (before 1995, series longas para a economia portuguesa, afterwards Pordata). Also plotted is a horizontal line with the average current account deficit of the last 10 years (-9.8%).
The pattern of deficits may not be new, but the size and duration seem quite unusual to me.
Update: Here is the picture, subtracting transfers from the current account.