WooCommerce: Add a surcharge based on the delivery country

country_surcharge.php

<?php
/**
 * Add a 1% surcharge to your cart / checkout based on delivery country
 * Taxes, shipping costs and order subtotal are all included in the surcharge amount
 *
 * Change $percentage to set the surcharge to a value to suit
 *
 * Add countries to array('US'); to include more countries to surcharge
 * http://en.wikipedia.org/wiki/ISO_3166-1#Current_codes for available alpha-2 country codes 
 *
 * Change in_array to !in_array to EXCLUDE the $countries array from surcharges
 *
 * Uses the WooCommerce fees API
 * Add to theme functions.php
 */
add_action( 'woocommerce_cart_calculate_fees','woocommerce_custom_country_surcharge' );
function woocommerce_custom_country_surcharge() {
    global $woocommerce;
 
	if ( is_admin() && ! defined( 'DOING_AJAX' ) ) {
		return;
	}

	$percentage = 0.01;
	$country = array( 'US' );

	if ( in_array( $woocommerce->customer->get_shipping_country(), $country ) ) {
		$surcharge = ( $woocommerce->cart->cart_contents_total + $woocommerce->cart->shipping_total ) * $percentage;
		$woocommerce->cart->add_fee( 'Surcharge', $surcharge, true, '' );
	}
	
	if ( $woocommerce->customer->get_shipping_state() == 'CO' ) ) {	
		$surcharge = ( $woocommerce->cart->cart_contents_total + $woocommerce->cart->shipping_total ) * $percentage;
		$woocommerce->cart->add_fee( 'Surcharge', $surcharge, true, 'standard' );
	}
    } 
	
}

state_surcharge.php

<?php
/**
 * Add a 1% surcharge to your cart / checkout based on delivery state
 * Taxes, shipping costs and order subtotal are all included in the surcharge amount
 *
 * Change $percentage to set the surcharge to a value to suit
 *
 * Change $state to set the state
 * Example: The state code for Colorado would be 'CO'
 * https://en.wikipedia.org/wiki/ISO_3166-2:US
 *
 * Uses the WooCommerce fees API
 * Add to theme functions.php
 */
add_action( 'woocommerce_cart_calculate_fees','woocommerce_custom_state_surcharge' );
function woocommerce_custom_state_surcharge() {
	global $woocommerce;
 
	if ( is_admin() && ! defined( 'DOING_AJAX' ) ) {
		return;
	}

	$percentage = 0.01;
	$state = 'CO';
	
	if ( $woocommerce->customer->get_shipping_state() == $state  ) ) {	
		$surcharge = ( $woocommerce->cart->cart_contents_total + $woocommerce->cart->shipping_total ) * $percentage;
		$woocommerce->cart->add_fee( 'Surcharge', $surcharge, true, 'standard' );
	}
}

Thanks for this snippet!

$county or $country ?

If I want to add a surcharge to all countries except the US would it be;

if ( !in_array( $woocommerce->customer->get_shipping_country(), $county ) ) :

Thanks for this snippet!

$county or $country ?

If I want to add a surcharge to all countries except the US would it be;

if ( !in_array( $woocommerce->customer->get_shipping_country(), $county ) ) :

Sorry for my late reply, @rplakas. I totally missed your comment and stumbled upon it. I corrected the typo and your code to exclude a country is correct. if ( ! in_array( $woocommerce->customer->get_shipping_country(), $county ) ) { ... } is the way to exclude a country.