Your country is desolate... — It is natural to take the words as describing the actual state of things when the prophet wrote. There had been such invasions in the days of Ahaz, in which Israel and Syria (Isaiah 7:1), Edom and the Philistines, had been conspicuous (2 Chronicles 28:17-18); and the reign of Hezekiah already had witnessed that of Sargon (Isaiah 20:1).
The Hebrew has no copulative verb, but joins subject and predicate together with the emphasis of abruptness: Your land — a desolation, and so on. The repetition of the word “strangers” is characteristic of Isaiah’s style.
As overthrown by strangers. — Conjectural readings give (1) “as the overthrow of Sodom;” (2) “as the overthrow of (i.e., wrought by) a rain-storm.” The word rendered “overthrown” is elsewhere applied only to the destruction of the cities of the plain (Deuteronomy 29:23; Amos 4:11; Jeremiah 49:18). So taken, the clause prepares the way for the fuller comparison of Isaiah 1:9-10.