Charles VIII of France and his sister Anne of Beaujeu set their sights on recovering Britanny in 1487.
The Duke of Brittany, Francis II was desperate to preserve Brittany independence but was old with no male heirs. Anne of Beaujeu wanted to marry her brother to Anne of Brittany.
This concerned Europe hugely (as it would make France even more powerful).
Ferdinand of Spain and Maximillian of the Habsburg Empire both tried to intervene by sending troops into Brittany.
For Henry this meant
Francis II of Brittany had sheltered Henry during his years in exile and he didn’t want France to gain even more power as it increased the likeliness of an invasion.
BUT - He didn’t want war with France / to antagonize so early into the reign/ he had been given help by the French with his invasion.