I need to block my opponent's immediate threat in the left column. They already have 'O' at positions (0,0) and (2,0), meaning they could win on their next move by completing the left column with (1,0). By placing my 'X' at (1,0), I prevent this immediate loss while also setting up potential win conditions for myself. This defensive move is critical as it's the only immediate threat on the board. Additionally, this position gives me future opportunities to potentially create a winning line across the middle row if I can later place at (1,2).