Why 広がる前 isn't 広がった前 in this sentence

Question

In this NHK Easy article there's the sentence:

しかし1年{ねん}に3000万{まん}人{にん}以上{いじょう}が来{き}ていたウイルスが広{ひろ}がる前{まえ}のときのようには、すぐに戻{もど}りません。

If I remove the part I'm having trouble with:

しかし1年{ねん}に3000万{まん}人{にん}以上{いじょう}が来{き}ていたときのようには、すぐに戻{もど}りません。

I understand that to mean "However like when over 30 million people had come a year, they won't go home right away."

So the full sentence probably means, "However like before the virus spread where over 30 million people had come a year, they won't go home right away."

But the virus did spread already, so wouldn't it be ウイルスが広がった前, or something like ウイルスが広がってきた前?

I think this is a similar situation to how if you say "before it started raining," you'd say 雨が降ってくる前に, instead of 降ってきた前に. But I'm having trouble applying that to this sentence.

So, I'm asking for help understanding what 広がる前 means in this sentence!

Answer 1

First, let's check the meaning of the sentence.

• 1年に3000万人以上が来ていた modifies ウイルスが広まる前のとき as a whole, not just ウイルス or ウイルスが広まる. I understand this relative clause is tricky; see this.
• You took the subject of 戻る wrong. This すぐに戻りません means "the number of tourists won't recover quickly", not "tourists won't go back home soon". See the original version of the article.

しかし1年に3000万人以上が来ていたウイルスが広がる前のときのようには、すぐに戻りません。
However, [the number of tourists] won't recover quickly to that of the pre-pandemic days when more than 30 million people a year came (to Japan).

Back to the main question, this 広がる前 is not 広がった前 because 前 almost always takes a dictionary form regardless of the tense of the main clause. 後 normally takes a past form.

• 食べる前に手を洗おう。
  Let's wash our hands before eating.
• 食べた後で手を洗おう。
  Let's wash our hands after eating.
• 食べる前に手を洗った。
  I washed my hands before eating.
• 食べた後で手を洗った。
  I washed my hands after eating.

Note that "3000万人が来ていた" is something that happened before the pandemic. Imagine a sentence like "ウイルスが広まる前に3000万人が日本に来ていた", and then read Blavius's answer to this question: How to appropriately pair tenses in subordinate and main clauses?