What vote is necessary to ratify or approve a treaty?

The President may form and negotiate, but the treaty must be advised and consented to by a two-thirds vote in the Senate. Only after the Senate approves the treaty can the President ratify it. Once it is ratified, it becomes binding on all the states under the Supremacy Clause.

The Constitution gives to the Senate the sole power to approve, by a two-thirds vote, treaties negotiated by the executive branch.

the roman army grew in size and became dominant in the mediterranean region.