Show State Field for WooCommerce
Be default, WooCommerce does not show Billing or Shipping State field on checkout page for many countries like Afghanistan, Austria, Åland Islands, Belgium, Bulgaria, Bahrain, Burundi, Benin etc.. and if you wanted to show them then you can use this plugin and use the settings page to select those countries.
For many counties in Europe like Denmark, Greece, Netherlands etc.. Billing / Shipping state field is compulsory for the checkout. So, you can use this plugin to have that field available on woocommerce checkout for all countries you want.