Trump's Truth Social announcement on the Greenland deal said adversary nations would need what before establishing any military presence there?

Explanation: Trump's announcement stated that US adversaries would be barred from establishing military bases or stationing personnel in Greenland unless they received written authorisation from the United States, reflecting Washington's stated intent to secure exclusive strategic control over access to the Arctic island going forward. This provision underscores the Arctic's growing geopolitical significance amid competition among major powers over emerging shipping routes and untapped mineral resources as polar ice continues to recede.