It was the same when in this year 1717 Cardinal Alberoni, at the instigation of Elizabeth of Parma the ambitious second wife of Philip V, attempted to regain Spain's lost possessions in Italy by an aggressive policy which threatened to involve Europe in war. Elizabeth's object was to obtain an independent sovereignty for her sons in her native country. Austria, France and England united to resist this attempt to reverse the settlement of Utrecht, and the States were induced to join with them in a quadruple alliance. It was not, however, their intention to take any active part in the hostilities which speedily brought Spain to reason, and led to the fall of Alberoni. But the Spanish queen had not given up her designs, and she found another instrument for carrying them out in Ripperda, a Groningen nobleman, who had originally gone to Spain as ambassador of the States. This able and scheming statesman persuaded Elizabeth that she might best attain her ends by an alliance with Austria, which was actually concluded at Vienna on April 1, 1725. This alliance alarmed France, England and Prussia, but was especially obnoxious to the Republic, for the emperor had in 1722 erected an East India Company at Ostend in spite of the prohibition placed by Holland and Spain in the treaties of 1714-15 upon Belgian overseas commerce. By the Treaty of Alliance in 1725 the Spanish crown recognised the Ostend Company and thus gave it a legal sanction. The States therefore, after some hesitation, became parties to a defensive alliance against Austria and Spain that had been signed by France, England and Prussia at Hanover in September, 1728. These groupings of the powers were of no long duration. The emperor, fearing an invasion of the Belgian provinces, first agreed to suspend the Ostend Company for seven years, and then, in order to secure the assent of the maritime powers to the Pragmatic Sanction, which guaranteed to his daughter, Maria Theresa, the succession to the Austrian hereditary domains, he broke with Spain and consented to suppress the Ostend Company altogether. The negotiations which took place at this time are very involved and complicated, but they ended in a revival of the old alliance between Austria and the maritime powers against the two Bourbon monarchies of France and Spain. This return to the old policy of William III was largely the work of Slingelandt, who had become council-pensionary on July 27, 1727.

Simon van Slingelandt, with the able assistance of his brother-in-law Francis Fagel, clerk of the States-General, was during the nine years in which he directed the foreign policy of the Republic regarded as one of the wisest and most trustworthy, as he was the most experienced statesman of his time. His aim was, in co-operation with England, to maintain by conciliatory and peaceful methods the balance of power. Lord Chesterfield, at that time the British envoy at the Hague, had the highest opinion of Slingelandt's powers; and the council-pensionary's writings, more especially his Pensees impartiales, published in 1729, show what a thorough grasp he had of the political situation. Fortunately the most influential ministers in England and France, Robert Walpole and Cardinal Fleury, were like-minded with him in being sincere seekers after peace. The Treaty of Vienna (March 18,1731), which secured the recognition by the powers of the Pragmatic Sanction, was largely his work; and he was also successful in preventing the question of the Polish succession, after the death of Augustus of Saxony in 1733, being the cause of the outbreak of a European war. In domestic policy Slingelandt, though profoundly dissatisfied with the condition of the Republic, took no steps to interfere with the form of government. He saw the defects of the stadholderless system plainly enough, but he had not, like Fagel, strong Orangist sympathies; and on his appointment as council-pensionary he pledged himself to support during his tenure of office the existing state of things. This undertaking he loyally kept, and his strong personality during his life-time alone saved Holland, and through Holland the entire Republic, from falling into utter ruin and disaster. At his death Antony van der Heim became council-pensionary under the same conditions as his predecessor. But Van der Heim, though a capable and hard-working official, was not of the same calibre as Slingelandt. The narrow and grasping burgher-regents had got a firm grip of power, and they used it to suppress the rights of their fellow-citizens and to keep in their own hands the control of municipal and provincial affairs. Corruption reigned everywhere; and the patrician oligarchy, by keeping for themselves and their relations all offices of profit, grew rich at the same time that the finances of the State fell into greater confusion. It was not a condition of things that could endure, should any serious crisis arise.