Like no other plague before, the AIDS epidemic threatens to wipe out an entire generation and leave another without parents.(Para.14)
Meaning: Unlike other plagues before, the AIDS plague is likely to kill an entire generation and make another generation lose their parents.
threaten: v. be a warning that one is going to hurt, punish, etc.; give warning of (sth. bad)
If you threaten me or use any force, I shall inform the police. 如果你威胁我，或动武的话，我就报警。
The verb "threaten" is often followed by an infinitive.
The fighting is threatening to turn into a war. 这场战斗有可能变成一场战争。
The father threatened to punish the child if the child did not obey his orders. 父亲威胁说要是孩子不听话，就要给以惩罚。