It was impossible first because—as experience shows that a three-mile movement of columns on a battlefield never coincides with the plans—the probability of Chichagov, Kutuzov, and Wittgenstein effecting a junction on time at an appointed place was so remote as to be tantamount to impossibility, as in fact thought Kutuzov, who when he received the plan remarked that diversions planned over great distances do not yield the desired results.
There are no more uses of "tantamount" in the book.
Show samples from other sources
Her statement was tantamount to an admission of guilt.
Not telling her is tantamount to aiding and abetting the enemy.