White isn't forced to play 2.d4. A good alternative is
2.c4, shown in the diagram. A natural reaction for Black is
2...d5. An alternative for Black is
2...e5 3.Nf3, but 2...e6 3.d4 d5 4.Nc3 Bb4 5.e5 is dubious.
If after 2...d5, White plays 3.exd5, Black can respond 3...cxd5, when 4.d4 transposes into the Panov Attack. Another try for White is 4.cxd5, when 4...Nf6 is better than 4...Qxd5 5.d4, which is similar to the Scandinavian Defense (aka Center Counter Game). Now White can play 5.Nc3 Nxd5 6.Nf3, followed by 6...e6, 6...Nc6, or 6...Nxc3. If 5.Bb5+ Nbd7, when White can't hold the extra Pawn for long.
Instead of 3...cxd5, 3...Nf6 transposes into the Scandinavian Defense, where it is known that White does better to play 4.d4 or 4.Nc3, than to snatch the c-Pawn. The variation 3.cxd5 cxd5 4.exd5 is just a transposition into 3.exd5 etc.
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