Yes, the United States does have obligations to Ukraine: https://en.wikipedia.org/wiki/Budapest_Memorandum https://en.wikipedia.org/wiki/Budapest_Memorandum In

Yes, the United States does have obligations to Ukraine: https://en.wikipedia.org/wiki/Budapest_Memorandum https://en.wikipedia.org/wiki/Budapest_Memorandum In exchange for them giving up nuclear weapons, the US, the UK, and Russia guaranteed its security and borders.