How does the initial WWII introduction differ fundamentally from modern transfer risks in terms of scale?

Answer

The Guam introduction was a singular, massive introduction event

The original event was driven by the immense logistical demands of war, resulting in one large introduction, while modern transfers are typically smaller, isolated stowaways resulting from the daily pace of global trade.

How does the initial WWII introduction differ fundamentally from modern transfer risks in terms of scale?
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