diff --git a/hwe/d_merge.php b/hwe/d_merge.php
index 8991d36b..0d6ed37d 100644
--- a/hwe/d_merge.php
+++ b/hwe/d_merge.php
@@ -85,7 +85,7 @@ if($ok == "수락") {
         $mylog[] = "<C>●</>양국 국력이 너무 높습니다. 통합 실패.";
     } elseif($mynation['gennum']+$younation['gennum'] > $avgnation['gennum']+$stdnation['gennum']) {
         $mylog[] = "<C>●</>양국 장수가 많습니다. 통합 실패.";
-    } elseif(!isClose($connect, $younation['nation'], $mynation['nation'])) {
+    } elseif(!isClose($younation['nation'], $mynation['nation'])) {
         $mylog[] = "<C>●</>인접한 국가가 아니므로 불가능합니다. 통합 실패.";
     } elseif($dip['state'] == 0) {
         $mylog[] = "<C>●</>아국과 교전중입니다. 통합 실패.";
diff --git a/hwe/d_surrender.php b/hwe/d_surrender.php
index cbf9f17d..3730b349 100644
--- a/hwe/d_surrender.php
+++ b/hwe/d_surrender.php
@@ -75,7 +75,7 @@ if($ok == "수락") {
         $mylog[] = "<C>●</>상대가 방랑군이므로 불가능합니다. 투항 실패.";
     } elseif($younation['power'] / $mynation['power'] <= 3) {
         $mylog[] = "<C>●</>아국과 상대국의 국력차이가 크지 않습니다. 투항 실패.";
-    } elseif($losecitynum != 0 && !isClose($connect, $younation['nation'], $mynation['nation'])) {
+    } elseif($losecitynum != 0 && !isClose($younation['nation'], $mynation['nation'])) {
         $mylog[] = "<C>●</>인접한 국가가 아니므로 불가능합니다. 투항 실패.";
     } elseif($dip['state'] == 0) {
         $mylog[] = "<C>●</>아국과 교전중입니다. 투항 실패.";
diff --git a/hwe/func.php b/hwe/func.php
index 435f5af0..d3c5aae9 100644
--- a/hwe/func.php
+++ b/hwe/func.php
@@ -2574,40 +2574,23 @@ function searchDistance(int $from, int $maxDist=99, bool $distForm = false) {
     }
 }
 
-function isClose($connect, $nation1, $nation2) {
-    $isClose = 0;
-    // $nation1의 모든 도시
-    $query = "select path from city where nation='$nation1'";
-    $result = MYDB_query($query, $connect) or Error(__LINE__.MYDB_error($connect),"");
-    $citycount = MYDB_num_rows($result);
+function isClose($nation1, $nation2) {
+    $db = DB::db();
 
-    // 국가의 모든 도시 검색
-    for($i=0; $i < $citycount; $i++) {
-        $city = MYDB_fetch_array($result);
+    $nation1Cities = [];
+    foreach($db->queryFirstColumn('SELECT city FROM city WHERE nation = %i', $nation1) as $city){
+        $nation1Cities[$city] = $city;
+    }
 
-        // 각 도시당 모든 인접 도시 플래그 세팅
-        $path = explode("|", $city['path']);
-        for($j=0; $j < count($path); $j++) {
-            $barrier[$path[$j]] = 1;
+    foreach($db->queryFirstColumn('SELECT city FROM city WHERE nation = %i', $nation2) as $city){
+        foreach(array_keys(CityConst::byID($city)->$path) as $adjCity){
+            if(key_exists($adjCity, $nation1Cities)){
+                return true;
+            }
         }
     }
 
-    // $nation2의 모든 도시 선택
-    $query = "select city from city where nation='$nation2'";
-    $result = MYDB_query($query, $connect) or Error(__LINE__.MYDB_error($connect),"");
-    $citycount = MYDB_num_rows($result);
-
-    for($i=0; $i < $citycount; $i++) {
-        $city = MYDB_fetch_array($result);
-        if(!key_exists($city['city'], $barrier)){
-            continue;
-        }
-        if($barrier[$city['city']] == 1) {
-            $isClose = 1;
-        }
-    }
-
-    return $isClose;
+    return false;
 }
 
 function CharExperience($exp, $personal) {
diff --git a/hwe/func_npc.php b/hwe/func_npc.php
index 7ab54fba..bda430f7 100644
--- a/hwe/func_npc.php
+++ b/hwe/func_npc.php
@@ -604,7 +604,7 @@ function processAI($connect, $no) {
                         for($i=0; $i < $nationCount; $i++) {
                             $youNation = MYDB_fetch_array($result);
 
-                            if(isClose($connect, $general['nation'], $youNation['nation'])) {
+                            if(isClose($general['nation'], $youNation['nation'])) {
                                 $command = EncodeCommand(0, 0, $youNation['nation'], 62);
                                 $query = "update nation set l12turn0='$command' where nation='{$general['nation']}'";
                                 MYDB_query($query, $connect) or Error("processAI09 ".MYDB_error($connect),"");
diff --git a/hwe/func_process_chief.php b/hwe/func_process_chief.php
index 476b048e..d445c5c1 100644
--- a/hwe/func_process_chief.php
+++ b/hwe/func_process_chief.php
@@ -655,7 +655,7 @@ function process_62($connect, &$general) {
         $log[] = "<C>●</>{$admin['month']}월:아국과 불가침중입니다. 선포 실패. <1>$date</>";
     } elseif($dipcount != 0) {
         $log[] = "<C>●</>{$admin['month']}월:상대국이 외교 진행중입니다. 선포 실패. <1>$date</>";
-    } elseif(!isClose($connect, $nation['nation'], $younation['nation'])) {
+    } elseif(!isClose($nation['nation'], $younation['nation'])) {
         $log[] = "<C>●</>{$admin['month']}월:인접하지 않았습니다. 선포 실패. <1>$date</>";
     } elseif($admin['year'] <= $admin['startyear']) {
         $log[] = "<C>●</>{$admin['month']}월:초반제한 해제 2년전부터 가능합니다. 선포 실패. <1>$date</>";
diff --git a/hwe/processing.php b/hwe/processing.php
index 78375e88..be502707 100644
--- a/hwe/processing.php
+++ b/hwe/processing.php
@@ -1712,7 +1712,7 @@ function command_51($connect, $turn, $command) {
     for($i=1; $i <= $count; $i++) {
         $nation = MYDB_fetch_array($result);
 
-        if($myNation['power'] / $nation['power'] <= 3 || !isClose($connect, $me['nation'], $nation['nation'])) {
+        if($myNation['power'] / $nation['power'] <= 3 || !isClose($me['nation'], $nation['nation'])) {
             echo "<option style=color:{$nation['color']};background-color:red; value={$nation['nation']}>【 {$nation['name']} 】</option>";
         } else {
             echo "<option style=color:{$nation['color']} value={$nation['nation']}>【 {$nation['name']} 】</option>";
@@ -1848,7 +1848,7 @@ function command_53($connect, $turn, $command) {
     for($i=1; $i <= $count; $i++) {
         $nation = MYDB_fetch_array($result);
 
-        if($myNation['power']+$nation['power'] > $cond1 || $myNation['gennum']+$nation['gennum'] > $cond2 || !isClose($connect, $me['nation'], $nation['nation'])) {
+        if($myNation['power']+$nation['power'] > $cond1 || $myNation['gennum']+$nation['gennum'] > $cond2 || !isClose($me['nation'], $nation['nation'])) {
             echo "<option style=color:{$nation['color']};background-color:red; value={$nation['nation']}>【 {$nation['name']} 】</option>";
         } else {
             echo "<option style=color:{$nation['color']} value={$nation['nation']}>【 {$nation['name']} 】</option>";